Narrow Search
 
 
Advanced Search

Browse All : Imager from 2007

Printer Friendly
1 2 3
1-50 of 115
     
     
Building Our New View of Tit …
Description This image of Titan's surface, obtained by Huygens' DISR imager, shows patterns of tectonic and fluid-flow activity.
Full Description This image of Titan's surface, obtained by Huygens' DISR imager, shows patterns of tectonic and fluid-flow activity. The tectonic patterns are indicated by blue lines, the drainage divide is indicated by the red line, flow directions are indicated by the green arrows. The Huygens landing site is marked by a white cross. Credits: ESA/NASA/JPL/University of Arizona
Date June 1, 2007
Huygens descending on Titan
Description Huygens descending on Titan
Full Description The artist's concept shows the European Space Agency's Huygens probe descent sequence. The animation shows the Huygens probe's entry, descent and landing, with the descent imager/spectral radiometer lamp turned on at the end. The probe was delivered to Saturn's moon Titan by the Cassini spacecraft, which is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. NASA supplied two instruments on the probe, the descent imager/spectral radiometer and the gas chromatograph mass spectrometer. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. *Credit:* NASA/JPL/ESA
Date August 28, 2007
A Burst of Color
title A Burst of Color
description New Horizons captured this unique view of Jupiter's moon Io with its color camera -- the Multispectral Visible Imaging Camera (MVIC) -- at 00:25 UT on March 1, 2007, from a range of 2.3 million kilometers (1.4 million miles). The image is centered at Io coordinates 4 degrees south, 162 degrees west, and was taken shortly before the complementary Long Range Reconnaissance Imager (LORRI) photo of Io released on March 13, which had higher resolution but was not in color. As in the LORRI picture, this processed image shows the nighttime glow of the Tvashtar volcano and its plume rising 330 kilometers (200 miles) into sunlight above Io's north pole. However, the MVIC picture reveals the intense red of the glowing lava at the plume source and the contrasting blue of the fine dust particles in the plume (similar to the bluish color of smoke), as well as more subtle colors on Io's sunlit crescent. The lower parts of the plume in Io's shadow, lit only by the much fainter light from Jupiter, are almost invisible in this rendition. Contrast has been reduced to show the large range of brightness between the plume and Io's disk. A component of the Ralph imaging instrument, MVIC has three broadband color filters: blue (480 nanometers), red (620 nm) and infrared (850 nm), as well as a narrow methane filter (890 nm). Because the camera was designed for the dim illumination at Pluto, not the much brighter sunlight at Jupiter, the red and infrared filters are overexposed on Io's dayside. This image is therefore composed from the blue and methane filters only, and the colors shown are only approximations to those that the eye would see. Nevertheless, the human eye would easily see the red color of the volcano and the blue color of the plume. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
A Brilliant Plume
title A Brilliant Plume
date 02.28.2007
description The Long Range Reconnaissance Imager (LORRI) on New Horizons captured another dramatic picture of Jupiter's moon Io and its volcanic plumes, 19 hours after the spacecraft's closest approach to Jupiter on Feb. 28, 2007. LORRI took this 75 millisecond exposure at 0035 Universal Time on March 1, 2007, when Io was 2.3 million kilometers (1.4 million miles) from the spacecraft. Io's dayside is deliberately overexposed to bring out faint details in the plumes and on the moon's night side. The continuing eruption of the volcano Tvashtar, at the 1 o'clock position, produces an enormous plume roughly 330 kilometers (200 miles) high, which is illuminated both by sunlight and "Jupiter light." The shadow of Io, cast by the Sun, slices across the plume. The plume is quite asymmetrical and has a complicated wispy texture, for reasons that are still mysterious. At the heart of the eruption incandescent lava, seen here as a brilliant point of light, is reminding scientists of the fire fountains spotted by the Galileo Jupiter orbiter at Tvashtar in 1999. The sunlit plume faintly illuminates the surface underneath. "New Horizons and Io continue to astonish us with these unprecedented views of the solar system's most geologically active body" says John Spencer, deputy leader of the New Horizons Jupiter Encounter Science Team and an Io expert from Southwest Research Institute. Because this image shows the side of Io that faces away from Jupiter, the large planet does not illuminate the moon's night side except for an extremely thin crescent outlining the edge of the disk at lower right. Another plume, likely from the volcano Masubi, is illuminated by Jupiter just above this lower right edge. A third and much fainter plume, barely visible at the 2 o'clock position, could be the first plume seen from the volcano Zal Patera. As in other New Horizons images of Io, mountains catch the setting Sun just beyond the terminator (the line dividing day and night). The most prominent, seen as a bright vertical line, is the edge of a plateau about 4.5 kilometers (15,000 feet) high, similar in altitude to the Colorado Rockies. Io itself has a diameter of 3,630 kilometers (about 2,250 miles). The image is centered at Io coordinates 4 degrees S, 165 degrees W. It has been processed to reduce contrast, in order to show details over the full 1000-to-1 brightness range of the original data. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
On Approach: Jupiter and Io
title On Approach: Jupiter and Io
date 01.08.2007
description This sequence of images was taken on Jan. 8, 2007, with the New Horizons Long Range Reconnaissance Imager (LORRI), while the spacecraft was about 81 million kilometers (about 50 million miles) from Jupiter. Jupiter's volcanic moon Io is to the right, the planet's Great Red Spot is also visible. The image was one of 11 taken during the Jan. 8 approach sequence, which signaled the opening of the New Horizons Jupiter encounter. Even in these early approach images, Jupiter shows different face than what previous visiting spacecraft -- such as Voyager 1, Galileo and Cassini -- have seen. Regions around the equator and in the southern tropical latitudes seem remarkably calm, even in the typically turbulent "wake" behind the Great Red Spot. The New Horizons science team will scrutinize these major meteorological features -- including the unexpectedly calm regions -- to understand the diverse variety of dynamical processes on the solar system's largest planet. These include the newly formed Little Red Spot, the Great Red Spot and a variety of zonal features. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
A Look from LEISA
title A Look from LEISA
date 02.24.2007
description On February 24, 2007, the LEISA (pronounced "Leesa") infrared spectral imager in the New Horizons Ralph instrument observed giant Jupiter in 250 narrow spectral channels. At the time the spacecraft was 6 million kilometers (nearly 4 million miles) from Jupiter, at that range, the LEISA imager can resolve structures about 400 kilometers (250 miles) across. LEISA observes in 250 infrared wavelengths, which range from 1.25 micrometers (µm) to 2.50 µm. The three images shown above from that dataset are at wavelengths of 1.27 µm (left), 1.53 µm (center) and 1.88 µm (right). The bright areas in the image frames are caused by solar radiation reflected from clouds and hazes in Jupiter's atmosphere. Dark areas correspond to atmospheric regions where solar radiation is absorbed before it can be reflected. The dark circular feature in the upper left of all three images is the shadow of Jupiter's innermost large moon, Io. Light at 1.53 µm (center frame) comes from relatively high in the atmosphere. The other two channels probe deeper atmospheric levels. Features that are bright in all three pictures come from high-altitude clouds. Features that are bright in the 1.27 and 1.88 µm channels, but darker in the 1.53-µm channel come from lower clouds. For example, there is an isolated circular feature (the "Little Red Spot") in the lower left of the 1.53-µm image. In the 1.27 and 1.88 µm data, this circular feature is surrounded by other structures. The implication is that the "Little Red Spot" is caused by a system that extends far up into the atmosphere, while other structures are lower. At closest approach to Jupiter on February 28, at a distance of about 2.5 million kilometers (1.4 million miles), LEISA's resolution was about three times better than it was on February 24. LEISA images made at that far-better resolution are still stored in the spacecraft's data recorder, awaiting downlink from New Horizons. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Jupiter's Rings
title Jupiter's Rings
date 02.24.2007
description The New Horizons Long Range Reconnaissance Imager (LORRI) snapped this photo of Jupiter's ring system on February 24, 2007, from a distance of 7.1 million kilometers (4.4 million miles). This processed image shows a narrow ring, about 1,000 kilometers (600 miles) wide, with a fainter sheet of material inside it. The faint glow extending in from the ring is likely caused by fine dust that diffuses in toward Jupiter. This is the outer tip of the "halo," a cloud of dust that extends down to Jupiter's cloud tops. The dust will glow much brighter in pictures taken after New Horizons passes to the far side of Jupiter and looks back at the rings, which will then be sunlit from behind. Jupiter's ring system was discovered in 1979, when astronomers spied it in a single image taken by the Voyager 1 spacecraft. Months later, Voyager 2 carried out more extensive imaging of the system. It has since been examined by NASA's Galileo and Cassini spacecraft, as well as by the Hubble Space Telescope and large ground-based observatories. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Ganymede's Shadow
title Ganymede's Shadow
date 01.09.2007
description The New Horizons Long Range Reconnaissance Imager (LORRI) took this photo of Jupiter at 20:42:01 UTC on January 9, 2007, when the spacecraft was 80 million kilometers (49.6 million miles) from the giant planet. The volcanic moon Io is to the left of the planet, the shadow of the icy moon Ganymede moves across Jupiter's northern hemisphere. Ganymede's average orbit distance from Jupiter is about 1 million kilometers (620,000 miles), Io's is 422,000 kilometers (262,000 miles). Both Io and Ganymede are larger than Earth's moon, Ganymede is larger than the planet Mercury. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
The Little Red Spot: Closest …
title The Little Red Spot: Closest View Yet
date 02.26.2007
description This is a mosaic of three New Horizons images of Jupiter's Little Red Spot, taken with the spacecraft's Long Range Reconnaissance Imager (LORRI) camera at 17:41 Universal Time on February 26 from a range of 3.5 million kilometers (2.1 million miles). The image scale is 17 kilometers (11 miles) per pixel, and the area covered measures 33,000 kilometers (20,000 miles) from top to bottom, two and one-half times the diameter of Earth. The Little Red Spot, a smaller cousin of the famous Great Red Spot, formed in the past decade from the merger of three smaller Jovian storms, and is now the second-largest storm on Jupiter. About a year ago its color, formerly white, changed to a reddish shade similar to the Great Red Spot, perhaps because it is now powerful enough to dredge up reddish material from deeper inside Jupiter. These are the most detailed images ever taken of the Little Red Spot since its formation, and will be combined with even sharper images taken by New Horizons 10 hours later to map circulation patterns around and within the storm. LORRI took the images as the Sun was about to set on the Little Red Spot. The LORRI camera was designed to look at Pluto, where sunlight is much fainter than it is at Jupiter, so the images would have been overexposed if LORRI had looked at the storm when it was illuminated by the noonday Sun. The dim evening illumination helped the LORRI camera obtain well-exposed images. The New Horizons team used predictions made by amateur astronomers in 2006, based on their observations of the motion of the Little Red Spot with backyard telescopes, to help them accurately point LORRI at the storm. These are among a handful of Jupiter system images already returned by New Horizons during its close approach to Jupiter. Most of the data being gathered by the spacecraft are stored onboard and will be downlinked to Earth during March and April 2007. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Jupiter Atmospheric Map
title Jupiter Atmospheric Map
date 01.14.2007
description Huge cyclonic storms, the Great Red Spot and the Little Red Spot, and wispy cloud patterns are seen in fascinating detail in this map of Jupiter's atmosphere obtained January 14-15, 2007, by the New Horizons Long Range Reconnaissance Imager (LORRI). The map combines information from 11 different LORRI images that were taken every hour over a 10-hour period -- a full Jovian day -- from 17:42 UTC on January 14 to 03:42 UTC on January 15. The New Horizons spacecraft was approximately 72 million kilometers (45 million miles) from Jupiter at the time. The LORRI pixels on the "globe" of Jupiter were projected onto a rectilinear grid, similar to the way flat maps of Earth are created. The LORRI pixel intensities were corrected so that every point on the map appears as if the sun were directly overhead, some image sharpening was also applied to enhance detail. The polar regions of Jupiter are not shown on the map because the LORRI images do not sample those latitudes very well and artifacts are produced during the map-projection process. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Tvashtar's Plume
title Tvashtar's Plume
date 02.28.2007
description This dramatic image of Io was taken by the Long Range Reconnaissance Imager (LORRI) on New Horizons at 11:04 Universal Time on February 28, 2007, just about 5 hours after the spacecraft's closest approach to Jupiter. The distance to Io was 2.5 million kilometers (1.5 million miles) and the image is centered at 85 degrees west longitude. At this distance, one LORRI pixel subtends 12 kilometers (7.4 miles) on Io. This processed image provides the best view yet of the enormous 290-kilometer (180-mile) high plume from the volcano Tvashtar, in the 11 o'clock direction near Io's north pole. The plume was first seen by the Hubble Space Telescope two weeks ago and then by New Horizons on February 26, this image is clearer than the February 26 image because Io was closer to the spacecraft, the plume was more backlit by the Sun, and a longer exposure time (75 milliseconds versus 20 milliseconds) was used. Io's dayside was deliberately overexposed in this picture to image the faint plumes, and the long exposure also provided an excellent view of Io's night side, illuminated by Jupiter. The remarkable filamentary structure in the Tvashtar plume is similar to details glimpsed faintly in 1979 Voyager images of a similar plume produced by Io's volcano Pele. However, no previous image by any spacecraft has shown these mysterious structures so clearly. The image also shows the much smaller symmetrical fountain of the plume, about 60 kilometers (or 40 miles) high, from the Prometheus volcano in the 9 o'clock direction. The top of a third volcanic plume, from the volcano Masubi, erupts high enough to catch the setting Sun on the night side near the bottom of the image, appearing as an irregular bright patch against Io's Jupiter-lit surface. Several Everest-sized mountains are highlighted by the setting Sun along the terminator, the line between day and night. This is the last of a handful of LORRI images that New Horizons is sending "home" during its busy close encounter with Jupiter -- hundreds of images and other data are being taken and stored onboard. The rest of the images will be returned to Earth over the coming weeks and months as the spacecraft speeds along to Pluto. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Moons around Jupiter
title Moons around Jupiter
date 01.09.2007
description The New Horizons Long Range Reconnaissance Imager (LORRI) took this photo of Jupiter at 20:42:01 UTC on January 9, 2007, when the spacecraft was 80 million kilometers (49.6 million miles) from the giant planet. The volcanic moon Io is to the left of the planet, the shadow of the icy moon Ganymede moves across Jupiter's northern hemisphere. Ganymede's average orbit distance from Jupiter is about 1 million kilometers (620,000 miles), Io's is 422,000 kilometers (262,000 miles). Both Io and Ganymede are larger than Earth's moon, Ganymede is larger than the planet Mercury. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Ganymede
title Ganymede
date 02.27.2007
description This is New Horizons' best image of Ganymede, Jupiter's largest moon, taken with the spacecraft's Long Range Reconnaissance Imager (LORRI) camera at 10:01 Universal Time on February 27 from a range of 3.5 million kilometers (2.2 million miles). The longitude of the disk center is 38 degrees West and the image scale is 17 kilometers (11 miles) per pixel. Dark patches of ancient terrain are broken up by swaths of brighter, younger material, and the entire icy surface is peppered by more recent impact craters that have splashed fresh, bright ice across the surface. With a diameter of 5,268 kilometers (3.273 miles), Ganymede is the largest satellite in the solar system. This is one of a handful of Jupiter system images already returned by New Horizons during its close approach to Jupiter. Most of the data being gathered by the spacecraft are stored onboard and will be downlinked to Earth during March and April 2007. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Io and Ganymede
title Io and Ganymede
date 01.17.2007
description The New Horizons Long Range Reconnaissance Imager (LORRI) took this 4-millisecond exposure of Jupiter and two of its moons at 01:41:04 UTC on January 17, 2007. The spacecraft was 68.5 million kilometers (42.5 million miles) from Jupiter, closing in on the giant planet at 41,500 miles (66,790 kilometers) per hour. The volcanic moon Io is the closest planet to the right of Jupiter, the icy moon Ganymede is to Io's right. The shadows of each satellite are visible atop Jupiter's clouds, Ganymede's shadow is draped over Jupiter's northwestern limb. Ganymede's average orbit distance from Jupiter is about 1.07 million kilometers (620,000 miles), Io's is 422,000 kilometers (262,000 miles). Both Io and Ganymede are larger than Earth's moon, Ganymede is larger than the planet Mercury. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Storms and Moons
title Storms and Moons
date 01.24.2007
description The New Horizons Long Range Reconnaissance Imager (LORRI) took this 2-millisecond exposure of Jupiter at 04:41:04 UTC on January 24, 2007. The spacecraft was 57 million kilometers (35.3 million miles) from Jupiter, closing in on the giant planet at 41,500 miles (66,790 kilometers) per hour. At right are the moons Io (bottom) and Ganymede, Ganymede's shadow creeps toward the top of Jupiter's northern hemisphere. Two of Jupiter's largest storms are visible, the Great Red Spot on the western (left) limb of the planet, trailing the Little Red Spot on the eastern limb, at slightly lower latitude. The Great Red Spot is a 300-year old storm more than twice the size of Earth. The Little Red Spot, which formed over the past decade from the merging of three smaller storms, is about half the size of its older and "greater" counterpart. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
An Eruption on Io
title An Eruption on Io
date 02.26.2007
description The first images returned to Earth by New Horizons during its close encounter with Jupiter feature the Galilean moon Io, snapped with the Long Range Reconnaissance Imager (LORRI) at 0840 UTC on February 26, while the moon was 2.5 million miles (4 million kilometers) from the spacecraft. Io is intensely heated by its tidal interaction with Jupiter and is thus extremely volcanically active. That activity is evident in these images, which reveal an enormous dust plume, more than 150 miles high, erupting from the volcano Tvashtar. The plume appears as an umbrella-shaped feature of the edge of Io's disk in the 11 o'clock position in the right image, which is a long-exposure (20-millisecond) frame designed specifically to look for plumes like this. The bright spots at 2 o'clock are high mountains catching the setting sun, beyond them the night side of Io can be seen, faintly illuminated by light reflected from Jupiter itself. The left image is a shorter exposure -- 3 milliseconds -- designed to look at surface features. In this frame, the Tvashtar volcano shows as a dark spot, also at 11 o'clock, surrounded by a large dark ring, where an area larger than Texas has been covered by fallout from the giant eruption. This is the clearest view yet of a plume from Tvashtar, one of Io's most active volcanoes. Ground-based telescopes and the Galileo Jupiter orbiter first spotted volcanic heat radiation from Tvashtar in November 1999, and the Cassini spacecraft saw a large plume when it flew past Jupiter in December 2000. The Keck telescope in Hawaii picked up renewed heat radiation from Tvashtar in spring 2006, and just two weeks ago the Hubble Space Telescope saw the Tvashtar plume in ultraviolet images designed to support the New Horizons flyby. Most of those images will be stored onboard the spacecraft for downlink to Earth in March and April. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Europa
title Europa
description This image of Jupiter's icy moon Europa, the first Europa image returned by New Horizons, was taken with the spacecraft's Long Range Reconnaissance Imager (LORRI) camera at 07:19 Universal Time on February 27, from a range of 3.1 million kilometers (1.9 million miles). The longitude of the disk center is 307 degrees West and the image scale is 15 kilometers (9 miles) per pixel. This is one of a series of images designed to look for landforms near Europa's terminator -- the line dividing day and night -- where low Sun angles highlight subtle topographic features. Europa's fractured icy surface is thought to overlie an ocean about 100 kilometers (60 miles) below the surface, and the New Horizons team will be analyzing these images for clues about the nature of the icy crust and the forces that have deformed it. Europa is about the size of Earth's moon, with a diameter of 3,130 kilometers (1.945 miles). This is one of a handful of images of the Jupiter system already returned by New Horizons during its close approach to Jupiter. Most of the data being gathered by the spacecraft are stored onboard and will be downlinked to Earth during March and April 2007. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Capturing Callisto
title Capturing Callisto
date 02.27.2007
description The New Horizons Long Range Reconnaissance Imager (LORRI) captured these two images of Jupiter's outermost large moon, Callisto, as the spacecraft flew past Jupiter in late February. New Horizons' closest approach distance to Jupiter was 2.3 million kilometers (1.4 million miles), not far outside Callisto's orbit, which has a radius of 1.9 million kilometers (1.2 million miles). However, Callisto happened to be on the opposite side of Jupiter during the spacecraft's pass through the Jupiter system, so these images, taken from 4.7 million kilometers (3.0 million miles) and 4.2 million kilometers (2.6 million miles) away, are the closest of Callisto that New Horizons obtained. Callisto's ancient, crater-scarred surface makes it very different from its three more active sibling satellites, Io, Europa and Ganymede. Callisto, 4,800 kilometers (3000 miles) in diameter, displays no large-scale geological features other than impact craters, and every bright spot in these images is a crater. The largest impact feature on Callisto, the huge basin Valhalla, is visible as a bright patch at the 10 o'clock position. The craters are bright because they have excavated material relatively rich in water ice from beneath the dark, dusty material that coats most of the surface. The two images show essentially the same side of Callisto - the side that faces Jupiter - under different illumination conditions. The images accompanied scans of Callisto's infrared spectrum with New Horizons' Linear Etalon Imaging Spectral Array (LEISA). The New Horizons science team designed these scans to study how the infrared spectrum of Callisto's water ice changes as lighting and viewing conditions change, and as the ice cools through Callisto's late afternoon. The infrared spectrum of water ice depends slightly on its temperature, and a goal of New Horizons when it reaches the Pluto system (in 2015) is to use the water ice features in the spectrum of Pluto's moon Charon, and perhaps on Pluto itself, to measure surface temperature. Callisto provided an ideal opportunity to test this technique on a much better-known body. The left image, taken at 05:03 Universal Time on February 27, 2007, is centered at 5 degrees south, 5 degrees west, and has a solar phase angle of 46 degrees. The right image was taken at 03:25 Universal Time on February 28, 2007. It is centered at 4 degrees south, 356 degrees west, and has a solar phase angle of 76 degrees. Released: April 5, 2007 Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
On 2007 February 8, the SOHO …
Description On 2007 February 8, the SOHO Extreme ultraviolet Imaging Telescope (EIT) became the first spaceborne solar imager to observe a complete solar cycle. EIT has now been observing for the mean length of a solar cycle, 11.1 years, since its first image was obtained on 1996 January 2. SOHO is the first solar observatory in space to observe a complete solar cycle. It has the unique opportunity of offering a retrospective reaching back over an entire solar cycle. So we can select and compare images and movies of the Sun almost exactly 10 years apart. We took a snapshot of the several weeks (January 15 - February 5, 2007) and pulled together frames from ten years ago (January 15 - February. 13, 1997). The Sun is fairly close to solar minimum (its lowest level of solar activity) for both of these periods, so one would expect both sequences to show a similar level of activity. In fact, it does. We see very few active regions and no major solar storms. It would appear that the 1997 frames are a little crisper with a bit more sharpness. Well, 11 years of staring at the Sun has probably taken a toll on the CCD imager. Still, what is most remarkable is that a single spacecraft has held up so well and produced such a long and valuable observation record, a record that scientists around the world are studying and analyzing every day.
The very bright object in th …
Description The very bright object in the upper left edge of our LASCO coronagraph image is comet C/2006 P1 (Comet McNaught). It was discovered on August 7th, 2006 by the hugely successful comet discoverer Rob McNaught. Then the comet was a very faint object, but it brightened considerably as it approached the Sun - to within just 0.17 astronomical units (the average distance between the Earth and Sun is about 150 million kilometers). As seen here (January 12, 2007) it is probably at its brightest because it is at or near perihelion, its closest approach to the Sun. This is probably the brightest comet SOHO has observed in its 11 years. Over the next several days its orbit will carry it down through our field of view in almost a vertical path [ http://soho.nascom.nasa.gov/hotshots/2007_01_08/C2006P1_C3_full.gif ]. So this is just a teaser for more images and movies to come. You can follow its progress on the SOHO Hot Shots page for this comet here [ http://sohowww.nascom.nasa.gov/hotshots/2007_01_08/ ]. Scientists are particularly interested in how its elongated ion tail will react to magnetic forces emanating from the Sun. The wide stretches of light to the sides of the comet are an aberration caused by the comet's brightness overwhelming the capabilities of our CCD imager. The smaller bright object below the Sun is Mercury. [ http://sohowww.nascom.nasa.gov/pickoftheweek/old/12jan2007/Johansen1.jpg ] It should be noted that countless skywatchers around the world have been excitedly trying to catch a view of this comet at sunrises and sunsets. And for good reason: it has become one of the brightest comets of the last century. For a short time (Jan. 13 - 15 or so) we believe the only way that anyone can observe the comet is through SOHO. As it gets further from the Sun in late January, observers mostly in the Southern Hemisphere, will get to see if it has brightened or not since its solar passage. No one really knows how that will turn out. The photo below, taken by Roger Johansen of Norway on January 6, 2007, shows the comet somewhat before it reached its greatest levels of brightness.
Hurricane Dean on August 19, …
Title Hurricane Dean on August 19, 2007
Abstract NASA's TRMM spacecraft observed this view of Hurricane Dean on August 19, 2007. At this time the storm was classified as a dangerous category four with sustained winds of 125 knots (138 mph). The cloud cover is taken by TRMM's Visible and Infrared Scanner(VIRS) and the GOES spacecraft. The rain structure is taken by TRMM's Tropical Microwave Imager (TMI) and TRMM's Precitation Radar(PR) instruments. TRMM looks underneath of the storm's clouds to reveal the underlying rain structure. Blue represents areas with at least 0.25 inches of rain per hour. Green shows at least 0.5 inches of rain per hour. Yellow is at least 1.0 inches of rain and red is at least 2.0 inches of rain per hour.
Completed 2007-08-19
Hurricane Dean on August 21, …
Title Hurricane Dean on August 21, 2007
Abstract NASA's TRMM spacecraft observed this view of Hurricane Dean on August 21, 2007. At this time the storm was classified as a category two with sustained winds of 90 knots (103.7 mph). The cloud cover is taken by TRMM's Visible and Infrared Scanner(VIRS) and the GOES spacecraft. The rain structure is taken by TRMM's Tropical Microwave Imager (TMI) and TRMM's Precitation Radar(PR) instruments. TRMM looks underneath of the storm's clouds to reveal the underlying rain structure. Grey represents areas with at least 0.25 inches of rain per hour. Green shows at least 0.5 inches of rain per hour. Yellow is at least 1.0 inches of rain and red is at least 2.0 inches of rain per hour.
Completed 2007-08-21
Hurricane Dean on August 21, …
Title Hurricane Dean on August 21, 2007
Abstract NASA's TRMM spacecraft observed this view of Hurricane Dean on August 21, 2007. At this time the storm was classified as a category two with sustained winds of 90 knots (103.7 mph). The cloud cover is taken by TRMM's Visible and Infrared Scanner(VIRS) and the GOES spacecraft. The rain structure is taken by TRMM's Tropical Microwave Imager (TMI) and TRMM's Precitation Radar(PR) instruments. TRMM looks underneath of the storm's clouds to reveal the underlying rain structure. Grey represents areas with at least 0.25 inches of rain per hour. Green shows at least 0.5 inches of rain per hour. Yellow is at least 1.0 inches of rain and red is at least 2.0 inches of rain per hour.
Completed 2007-08-21
STEREO Coronal Mass Ejection …
Title STEREO Coronal Mass Ejection: From the EUVI to HI-2
Abstract This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager
Completed 2007-02-26
STEREO Coronal Mass Ejection …
Title STEREO Coronal Mass Ejection: From the EUVI to HI-2
Abstract This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager
Completed 2007-02-26
STEREO Coronal Mass Ejection …
Title STEREO Coronal Mass Ejection: From the EUVI to HI-2
Abstract This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager
Completed 2007-02-26
STEREO Coronal Mass Ejection …
Title STEREO Coronal Mass Ejection: From the EUVI to HI-2
Abstract This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager
Completed 2007-02-26
STEREO Coronal Mass Ejection …
Title STEREO Coronal Mass Ejection: From the EUVI to HI-2
Abstract This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager
Completed 2007-02-26
STEREO Coronal Mass Ejection …
Title STEREO Coronal Mass Ejection: From the EUVI to HI-2
Abstract This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager
Completed 2007-02-26
Solar Eclipse Video Captured …
Name of Image Solar Eclipse Video Captured by STEREO-B
Date of Image 2007-02-25
Full Description No human has ever witnessed a solar eclipse quite like the one captured on this video. The NASA STEREO-B spacecraft, managed by the Goddard Space Center, was about a million miles from Earth , February 25, 2007, when it photographed the Moon passing in front of the sun. The resulting movie looks like it came from an alien solar system. The fantastically-colored star is our own sun as STEREO sees it in four wavelengths of extreme ultraviolet light. The black disk is the Moon. When we observe a lunar transit from Earth, the Moon appears to be the same size as the sun, a coincidence that produces intoxicatingly beautiful solar eclipses. The silhouette STEREO-B saw, on the other hand, was only a fraction of the Sun. The Moon seems small because of the STEREO-B location. The spacecraft circles the sun in an Earth-like orbit, but it lags behind Earth by one million miles. This means STEREO-B is 4.4 times further from the Moon than we are, and so the Moon looks 4.4 times smaller. This version of the STEREO-B eclipse movie is a composite of data from the coronagraph and extreme ultraviolet imager of the spacecraft. STEREO-B has a sister ship named STEREO-A. Both are on a mission to study the sun. While STEREO-B lags behind Earth, STEREO-A orbits one million miles ahead ("B" for behind, "A" for ahead). The gap is deliberate as it allows the two spacecraft to capture offset views of the sun. Researchers can then combine the images to produce 3D stereo movies of solar storms. The two spacecraft were launched in Oct. 2006 and reached their stations on either side of Earth in January 2007.
Heavy Rain in the US Midwest
Title Heavy Rain in the US Midwest
Description Towering clouds characterize violent thunderstorms in northern Texas and southern Oklahoma in this three-dimensional image. The Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite took the image on May 8, 2007, at 7:30 p.m. local time. The tallest clouds shown here reach a height of 14 kilometers (8.7 miles) above the Earth's surface. Thunderstorms form as warm, fast-rising air carries heat from the Earth's surface higher into the atmosphere. When water vapor in the air cools in the atmosphere, it forms clouds. Over time, the clouds grow, and rain begins to fall. The higher the air rises before forming clouds, the taller the resulting cloud will be and the more violent the storm will become. Violent thunderstorms often bring heavy rain or hail, lightning, strong winds, and occasionally, tornadoes. It is not unusual then, that the towering clouds coincide with areas of heavy rainfall, as shown in red in the lower image. A pale, transparent white band marks out the path of TRMM's precipitation radar in both images. The satellite swath runs roughly east-west across the lower image, which is oriented with north up. The top image has been rotated so that the path of the precipitation radar runs vertically across the image. The perspective is similar to one you might have if you were looking west across Texas from high above its eastern border. The three-dimensional image, taken by the precipitation radar, shows two clusters of storms, one near the Texas panhandle and one over the northeast border. The lower image illustrates how intensely the rain was falling within a line of storms. The most intense rain is marked in red, while areas of light rain are blue. The TRMM Microwave Imager recorded these rain rates, and they laid over an infrared image captured by the TRMM Visible Infrared Scanner. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Image by Hal Pierce, NASA Goddard Space Flight Center
Heavy Rain in the US Midwest
Title Heavy Rain in the US Midwest
Description Towering clouds characterize violent thunderstorms in northern Texas and southern Oklahoma in this three-dimensional image. The Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite took the image on May 8, 2007, at 7:30 p.m. local time. The tallest clouds shown here reach a height of 14 kilometers (8.7 miles) above the Earth's surface. Thunderstorms form as warm, fast-rising air carries heat from the Earth's surface higher into the atmosphere. When water vapor in the air cools in the atmosphere, it forms clouds. Over time, the clouds grow, and rain begins to fall. The higher the air rises before forming clouds, the taller the resulting cloud will be and the more violent the storm will become. Violent thunderstorms often bring heavy rain or hail, lightning, strong winds, and occasionally, tornadoes. It is not unusual then, that the towering clouds coincide with areas of heavy rainfall, as shown in red in the lower image. A pale, transparent white band marks out the path of TRMM's precipitation radar in both images. The satellite swath runs roughly east-west across the lower image, which is oriented with north up. The top image has been rotated so that the path of the precipitation radar runs vertically across the image. The perspective is similar to one you might have if you were looking west across Texas from high above its eastern border. The three-dimensional image, taken by the precipitation radar, shows two clusters of storms, one near the Texas panhandle and one over the northeast border. The lower image illustrates how intensely the rain was falling within a line of storms. The most intense rain is marked in red, while areas of light rain are blue. The TRMM Microwave Imager recorded these rain rates, and they laid over an infrared image captured by the TRMM Visible Infrared Scanner. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Image by Hal Pierce, NASA Goddard Space Flight Center
Heavy Rain in the US Midwest
Title Heavy Rain in the US Midwest
Description Towering clouds characterize violent thunderstorms in northern Texas and southern Oklahoma in this three-dimensional image. The Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite took the image on May 8, 2007, at 7:30 p.m. local time. The tallest clouds shown here reach a height of 14 kilometers (8.7 miles) above the Earth's surface. Thunderstorms form as warm, fast-rising air carries heat from the Earth's surface higher into the atmosphere. When water vapor in the air cools in the atmosphere, it forms clouds. Over time, the clouds grow, and rain begins to fall. The higher the air rises before forming clouds, the taller the resulting cloud will be and the more violent the storm will become. Violent thunderstorms often bring heavy rain or hail, lightning, strong winds, and occasionally, tornadoes. It is not unusual then, that the towering clouds coincide with areas of heavy rainfall, as shown in red in the lower image. A pale, transparent white band marks out the path of TRMM's precipitation radar in both images. The satellite swath runs roughly east-west across the lower image, which is oriented with north up. The top image has been rotated so that the path of the precipitation radar runs vertically across the image. The perspective is similar to one you might have if you were looking west across Texas from high above its eastern border. The three-dimensional image, taken by the precipitation radar, shows two clusters of storms, one near the Texas panhandle and one over the northeast border. The lower image illustrates how intensely the rain was falling within a line of storms. The most intense rain is marked in red, while areas of light rain are blue. The TRMM Microwave Imager recorded these rain rates, and they laid over an infrared image captured by the TRMM Visible Infrared Scanner. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Image by Hal Pierce, NASA Goddard Space Flight Center
Hurricane Henriette
Title Hurricane Henriette
Description Although not a very powerful storm, Hurricane Henriette was responsible for seven fatalities along Mexico's Pacific coast as of September 6, 2007, said news reports. Henriette struck hardest in the resort town of Acapulco. Though the storm never passed closer than 70 miles to the town, heavy rains along the coast saturated the ground, leading to mudslides. These slides were the leading cause of fatalities. This image shows Hurricane Henriette as a Category 1 [ http://www.nhc.noaa.gov/aboutsshs.shtml ] hurricane, as seen by the Tropical Rainfall Measuring Mission (TRMM) [ http://trmm.gsfc.nasa.gov/ ] satellite at 8:50 a.m. local time (14:50 UTC) on September 5. At that time, the storm was moving north-northwest over the Gulf of California after it had made its initial landfall on the Baja Peninsula. The image shows the horizontal pattern of rain intensity within the storm, with the heaviest rain in red and the lightest rain in blue. A break in the circular rainfall field in the southwest corner of the storm reveals a large, ragged eye. A large eye only partially surrounded by rain is a hallmark of a system that is decaying or has been weakened. In this case, Henriette was likely breaking up after its interaction with land. Most of the rain is north and east of the center, with bands of heavy rain located just offshore of mainland Mexico (dark red areas). Henriette was expected to dump several inches of rain over mainland Mexico, and possibly bring some rain to the southwestern regions of the United States. The TRMM satellite was placed into service in November 1997. From its low-earth orbit, TRMM provides valuable images and information on storm systems around the tropics using a combination of passive microwave and active radar sensors, including the first precipitation radar in space. In this image, the rain rates in the center of the swath are from the TRMM Precipitation Radar, and those in the outer swath come from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Image produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Hurricane Lorenzo
Title Hurricane Lorenzo
Description Tropical Storm Lorenzo increased in strength and was upgraded to a hurricane with wind speeds of 130 kilometers per hour (80 miles per hour or 70 knots) a few hours before it came ashore about 40 miles south-southeast of Tuxpan, Mexico. Lorenzo weakened after it came ashore, but it was still expected to produce torrential rainfall as it moved slowly inland. This image was made from data captured by the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite at 10:27 p.m. local time on September 27, 2007 (03:27 UTC, September 28). It shows very heavy rain of more than 50 millimeters per hour (2 inches per hour) falling in the eyewall of the hurricane as it was coming ashore in Mexico. Rain rates in the center of the satellite swath are based on the TRMM Precipitation Radar, and those in the outer swath are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data of clouds observed by the TRMM Visible Infrared Scanner. Image and caption courtesy Hal Pierce (SSAI/NASA GSFC)
Melting Anomalies on Greenla …
Title Melting Anomalies on Greenland in 2007
Description The year 2007 marked an overall rise in the summertime melting trend over the entire Greenland ice sheet. In particular, melting in areas above 2,000 meters (about 6,560 feet) rose 150 percent above the long-term average, with melting occurring on 25-30 more days in 2007 than the average in the previous 19 years. This image shows the Greenland melt anomaly, measured as the difference between the number of days on which melting occurred in 2007 compared to the average annual melting days from 1988-2006. The areas with the highest amounts of additional melt days appear in red, and areas with below-average melt days appear in blue. Although faint streaks of blue appear along the coastlines, namely in northwestern and southeastern Greenland, red and orange predominate, especially in the south. This image is based on microwave-frequency data from the Special Sensor Microwave/Imager (SSM/I) on the Defense Meteorological Satellite Program. Snow and ice naturally emit microwave energy, but the signal is very different for dry versus wet snow. These differences allow sensors to detect the presence of melting snow on the surface of the ice sheet as well as deeper in the snow and ice pack. In addition to calculating Greenland's melting day anomaly, Marco Tedesco, a research scientist at the Joint Center for Earth Systems Technology, also calculated a melting index—a scale created by multiplying the number of days that melting took place by the area where melting occurred. Melting index in April and May of 2007 in high-altitude areas was very low, but in June melting jumped unexpectedly and remained high for the rest of the summer. The melting index in lower altitude areas of Greenland in 2007 was also higher than average by 30 percent, though it did not break any record. The year 2007 fell at fifth place for the highest melting index, after 2005, 2002, 1998 and 2004. Increasing melting snow over Greenland can influence the Earth in several ways. Aside from contributing to direct sea level rise, melting—especially along the coast—can speed up glaciers since the meltwater can percolate down to the ice-bedrock interface, acting as a lubricant between the ice and the bedrock. The faster glaciers flow, the more water enters the ocean and the greater the potential for sea level rise. Although some of the snow melting at high elevations is unlikely to reach the ocean, melting snow at high altitudes can still affect Earth's energy budget. Melted and refrozen snow can absorb up to four times more energy than fresh, unthawed snow. As a result, snow melt can change the amount of solar radiation the Earth absorbs versus the amount it reflects. Image and interpretation by Marco Tedesco, Joint Center for Earth Systems Technology, NASA Goddard Space Flight Center, University of Maryland at Baltimore County.
Plume from Jebel at Tair
Title Plume from Jebel at Tair
Description Jebel at Tair, a small volcanic island in the Red Sea, which had erupted [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14559 ] in late September 2007, released a volcanic plume on November 8, 2007. The Advanced Land Imager (ALI) [ http://eo1.gsfc.nasa.gov/Technology/ALIhome1.htm ] on NASA's EO-1 [ http://eo1.gsfc.nasa.gov/ ] captured this image the same day. In this image, volcanic plume appears as billowing puffs of white emanating from the summit. Evidence of earlier lava flows appears as dark stains on the volcano's slopes. Midway between Yemen and Eritrea, Jebel at Tair [ http://www.volcano.si.edu/world/volcano.cfm?vnum=0201-01= ] is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and rocks ejected by previous eruptions. Jebel at Tair is known by multiple names and spellings. It has alternately been referred to as Jabal al-Tair, Jabal al-Tayr, Tair Island, Al-Tair Island, Djebel Teyr, and Jibbel Tir. Image courtesy Ashley Davies, NASA Jet Propulsion Laboratory.
Record Sea Ice Minimum
Title Record Sea Ice Minimum
Description Arctic sea ice reached a record low [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17782 ] in September 2007, below the previous record set in 2005 and substantially below the long-term average. This image shows the Arctic as observed by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA's Aqua [ http://aqua.nasa.gov ] satellite on September 16, 2007. In this image, blue indicates open water, white indicates high sea ice concentration, and turquoise indicates loosely packed sea ice. The black circle at the North Pole results from an absence of data as the satellite does not make observations that far north. Three contour lines appear on this image. The red line is the 2007 minimum, as of September 15, about the same time the record low was reached, and it almost exactly fits the sea ice observed by AMSR-E. The green line indicates the 2005 minimum, the previous record low. The yellow line indicates the median minimum from 1979 to 2000. The contour lines in this image show sea ice extent, as reported [ http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html ] by the National Snow and Ice Data Center (NSIDC). Another measure of sea ice is area, and this value was initially reported as a record low by The Cryosphere Today [ http://arctic.atmos.uiuc.edu/cryosphere/ ] at the University of Illinois. A simple analogy for these terms is a slice of Swiss cheese. Extent counts everything inside the slice's perimeter as cheese-filled whereas area subtracts the holes from the total amount. A more technical explanation of area versus extent involves pixels. A pixel is the smallest possible unit of the satellite image, and it can have only one value. (How much of the planet's surface a pixel covers depends on the satellite sensor.) Measurements of sea ice area total the amount of sea ice in each pixel. Extent, as measured by NSIDC, sets a threshold of 15 percent, and counts any pixel above that threshold as completely ice-filled. Consequently, estimates of sea ice extent are higher than estimates of sea ice area. NASA image created by Jesse Allen, using AMSR-E data courtesy of the National Snow and Ice Data Center (NSIDC), and sea ice extent contours courtesy of Terry Haran and Matt Savoie, NSIDC, [ http://www.nsidc.org/ ] based on Special Sensor Microwave Imager (SSM/I) data.
Fires in Southern California
Title Fires in Southern California
Description From the mountains of the Cleveland National Forest east of San Diego, the Harris Fire came racing down toward the San Diego suburbs on October 23, 2007. This infrared-enhanced satellite image from NASA's Advanced Land Imager sensor on the EO-1 satellite shows the flames reaching the Sweetwater Reservoir. Burning areas appear bright pink, smoke is transparent blue, vegetation is bright green, and paved or bare surfaces are purplish-gray. The large burned area (only part of which is visible in this scene) appears as a reddish-brown area in the lower-right corner of the image. Bright pink spots within the burned area indicate fire is still active in the interior of the blaze as well as around the perimeter. According to the October 24 morning report from the National Interagency Fire Center, the Harris Fire had burned about 72,000 acres and was only 10 percent contained. NASA image courtesy of Lawrence Ong.
Fires in Southern California
Title Fires in Southern California
Description By October 25, the Witch Fire burning in San Diego County, California, had started to subside. Fierce winds that propelled the flames across 197,990 acres quieted, giving fire fighters a chance to battle the flames. However, the massive fire was still just 30 percent contained when NASA's Advanced Land Imager sensor on the EO-1 satellite captured this image on October 25, 2007. The image shows the fire burning around Ramona, California, north of downtown San Diego. Flames glow red, yellow, and orange in the infrared-enhanced image, and plumes of smoke are faintly visible traces of blue. The drought-dry vegetation is deceptively green, though irrigated lawns are brighter in tone than natural vegetation. Dark brown-red covers land charred in the wake of the flames. The top image shows one front of the fire in the mountains immediately east of Ramona. The flames follow the jagged line of the ridge. The west side of the mountain is burned, providing a clearer view of the rough terrain that made fighting the fire so difficult. The burn scar also makes it easier to see the canyons that channeled the strong Santa Ana winds from inland high-altitude deserts in the east toward the Pacific Ocean in the west. The image only shows part of the burned area. The fire extended much farther to the west. The lower image shows sections of the fire near the western edge of Ramona. Neatly shaped lawns and silver-blue roof-tops reveal that this is a residential area. Interstate 15, which runs vertically through the image, was flanked by two actively burning segments of the Witch Fire. Spots of red within the burned landscape point to hotspots where the fire still smolders. The San Diego Tribune reported that firefighters expected to contain the fire by October 28. As of October 26, the Witch Fire had killed two people, injured an additional 14, and destroyed 1,061 homes and 30 commercial properties, said the Tribune. NASA image courtesy of Lawrence Ong.
Super Typhoon Wipha
Title Super Typhoon Wipha
Description The top image provides a unique view of the remains of Typhoon Wipha about 16 hours after the center of the storm made landfall near Cangnan, in southern Zhejiang province on the east coast of China. The image was taken by the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite at 7:11 pm local time (11:11 UTC) on September 19, 2007, and it shows the horizontal pattern of rain intensity within the storm. Rain rates in the center of the swath are from the TRMM Precipitation Radar, and those in the outer swath come from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. At this stage, Wipha no longer had a defined eye. Instead, the center of circulation was surrounded by broken areas of mostly light rain (blue areas). Most of the rain is farther to the north (larger blue area). Wipha was a Category 3 typhoon just before landfall, with sustained winds estimated at 100 knots (115 mph) by the Joint Typhoon Warning Center. At the time of the TRMM overpass on September 19, sustained winds were down to 50 knots (58 mph). Most tropical cyclones weaken quickly after making landfall. Without active, deep convection near the center to fuel the storm, the circulation will spin down. The change in shape and intensity are evident in comparing the September 19 image to an image made with data collected on September 18. Just before Wipha made landfall, its center was defined by circular bands of heavy rain, shown in green and yellow in the lower image. A small band of extremely intense rain, depicted in red, is southeast of the storm's center. By the next day, Wipha no longer exhibited the structured bands of rain seen on September 18. Wipha became a tropical storm on September 16 in the central Philippine Sea. The system tracked northwestward and quickly intensified to a Category 4 storm as it approached Taiwan. Although the center passed northeast of Taiwan, Wipha was blamed for one fatality on the island. As of September 20, two persons had been reported dead in China as a result of the storm, said news reports. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Super Typhoon Wipha
Title Super Typhoon Wipha
Description The top image provides a unique view of the remains of Typhoon Wipha about 16 hours after the center of the storm made landfall near Cangnan, in southern Zhejiang province on the east coast of China. The image was taken by the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite at 7:11 pm local time (11:11 UTC) on September 19, 2007, and it shows the horizontal pattern of rain intensity within the storm. Rain rates in the center of the swath are from the TRMM Precipitation Radar, and those in the outer swath come from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. At this stage, Wipha no longer had a defined eye. Instead, the center of circulation was surrounded by broken areas of mostly light rain (blue areas). Most of the rain is farther to the north (larger blue area). Wipha was a Category 3 typhoon just before landfall, with sustained winds estimated at 100 knots (115 mph) by the Joint Typhoon Warning Center. At the time of the TRMM overpass on September 19, sustained winds were down to 50 knots (58 mph). Most tropical cyclones weaken quickly after making landfall. Without active, deep convection near the center to fuel the storm, the circulation will spin down. The change in shape and intensity are evident in comparing the September 19 image to an image made with data collected on September 18. Just before Wipha made landfall, its center was defined by circular bands of heavy rain, shown in green and yellow in the lower image. A small band of extremely intense rain, depicted in red, is southeast of the storm's center. By the next day, Wipha no longer exhibited the structured bands of rain seen on September 18. Wipha became a tropical storm on September 16 in the central Philippine Sea. The system tracked northwestward and quickly intensified to a Category 4 storm as it approached Taiwan. Although the center passed northeast of Taiwan, Wipha was blamed for one fatality on the island. As of September 20, two persons had been reported dead in China as a result of the storm, said news reports. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Tropical Cyclone Favio
Title Tropical Cyclone Favio
Description ) satellite on February 20 and February 22, 2007. TRMM was placed into its low-earth orbit in November 1997 to measure rainfall from space, however, it has also served as a valuable platform for monitoring tropical cyclones, especially over remote parts of the open ocean. The images show the rainfall intensity. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. TRMM shows that Favio was a well-organized storm on February 20 (top) with a central eye (dark blue area in the center) surrounded by an eyewall containing heavy rainfall (dark red areas). The storm is also very symmetric with good "banding" in the rain field, demonstrated by the tightly curved bands of moderate rain (green areas) spiraling in towards the center. These features are the hallmarks of a mature, intense tropical cyclone. Though the cyclone did not strike Madagascar, the red areas indicate that it dumped heavy rains on the southern tip of the island. As Favio crossed the Mozambique Channel it reached a peak intensity of 232 kilometers per hour (144 miles per hour, or 125 knots) on the early morning of February 22, making it a Category 4 storm. The cyclone then weakened slightly before slamming into southern Mozambique with sustained winds estimated at 204 km/hr (127 mph, 110 knots). TRMM took the lower image on February 22 soon after Favio made landfall in Mozambique. The image shows that although the eye was not as well defined as in the earlier image, the circulation is still robust, the spiral rainbands (green arcs) are still well defined. Maximum sustained winds were still estimated to be 167 km/hr (114 mph, 90 knots) at the time of this image but quickly diminished thereafter. The bands of heavy rain shown in this image triggered floods [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14146 ] along rivers in Central Mozambique. Unfortunately for Mozambique, the storm-induced floods follow additional serious flooding on the Zambezi River [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14125 ] to the north. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC)., These images track Cyclone Favio as it brushed the southern tip of the island of Madagascar, and then continued on to Mozambique. The storm came ashore over southern Mozambique on February 22, 2007, as a strong Category 3 storm. As of February 28, news reports had attributed four fatalities to the storm in Vilanculos, a coastal tourist town where the storm made landfall. Favio began as a tropical disturbance on February 11, 2007, in the central Indian Ocean south of Diego Garcia in the Chagos Archipelago. Slow to intensify, the system finally became a tropical storm three days later on February 14. Favio remained a tropical storm for the next several days as it made its way through the west-central Indian Ocean east of Mauritius, and finally began to intensify as it neared Madagascar. It became a Category 1 cyclone on February 19. As it rounded the southern tip of Madagascar, Favio continued to intensify and reached Category 3 intensity on February 20. The cyclone then took a more northwesterly path as it entered the Mozambique Channel. These images of the storm were taken by the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]
Tropical Cyclone Favio
Title Tropical Cyclone Favio
Description ) satellite on February 20 and February 22, 2007. TRMM was placed into its low-earth orbit in November 1997 to measure rainfall from space, however, it has also served as a valuable platform for monitoring tropical cyclones, especially over remote parts of the open ocean. The images show the rainfall intensity. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. TRMM shows that Favio was a well-organized storm on February 20 (top) with a central eye (dark blue area in the center) surrounded by an eyewall containing heavy rainfall (dark red areas). The storm is also very symmetric with good "banding" in the rain field, demonstrated by the tightly curved bands of moderate rain (green areas) spiraling in towards the center. These features are the hallmarks of a mature, intense tropical cyclone. Though the cyclone did not strike Madagascar, the red areas indicate that it dumped heavy rains on the southern tip of the island. As Favio crossed the Mozambique Channel it reached a peak intensity of 232 kilometers per hour (144 miles per hour, or 125 knots) on the early morning of February 22, making it a Category 4 storm. The cyclone then weakened slightly before slamming into southern Mozambique with sustained winds estimated at 204 km/hr (127 mph, 110 knots). TRMM took the lower image on February 22 soon after Favio made landfall in Mozambique. The image shows that although the eye was not as well defined as in the earlier image, the circulation is still robust, the spiral rainbands (green arcs) are still well defined. Maximum sustained winds were still estimated to be 167 km/hr (114 mph, 90 knots) at the time of this image but quickly diminished thereafter. The bands of heavy rain shown in this image triggered floods [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14146 ] along rivers in Central Mozambique. Unfortunately for Mozambique, the storm-induced floods follow additional serious flooding on the Zambezi River [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14125 ] to the north. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC)., These images track Cyclone Favio as it brushed the southern tip of the island of Madagascar, and then continued on to Mozambique. The storm came ashore over southern Mozambique on February 22, 2007, as a strong Category 3 storm. As of February 28, news reports had attributed four fatalities to the storm in Vilanculos, a coastal tourist town where the storm made landfall. Favio began as a tropical disturbance on February 11, 2007, in the central Indian Ocean south of Diego Garcia in the Chagos Archipelago. Slow to intensify, the system finally became a tropical storm three days later on February 14. Favio remained a tropical storm for the next several days as it made its way through the west-central Indian Ocean east of Mauritius, and finally began to intensify as it neared Madagascar. It became a Category 1 cyclone on February 19. As it rounded the southern tip of Madagascar, Favio continued to intensify and reached Category 3 intensity on February 20. The cyclone then took a more northwesterly path as it entered the Mozambique Channel. These images of the storm were taken by the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]
Tropical Cyclone Gonu
Title Tropical Cyclone Gonu
Description At one time, Cyclone Gonu was a powerful Category 5 storm packing sustained winds of 255 kilometers per hour (160 miles per hour), according to the Joint Typhoon Warning Center, [ https://metocph.nmci.navy.mil/jtwc.php ] and on a course towards Oman. This made it the most powerful cyclone ever to threaten the Arabian Peninsula since record keeping began back in 1945. Tropical cyclones do on occasion form in the Arabian Sea, but they rarely exceed tropical storm intensity. In 2006, Tropical Storm Mukda was the only system to form in the region, and it remained well out to sea before dissipating. Gonu became a tropical storm in the morning (local time) of June 2, 2007, in the east-central Arabian Sea. After some initial fluctuations in direction, the storm settled on a northwesterly track and began to intensify. Gonu went from tropical storm intensity to a Category 2 Tropical Cyclone [ http://www.nhc.noaa.gov/aboutsshs.shtml ] on the night of June 3. Overnight, it developed into a Category 4 storm with winds estimated at 210 km/hr (132 mph). The Tropical Rainfall Measuring Mission (TRMM) [ http://trmm.gsfc.nasa.gov/ ], captured this image of Gonu as the storm was moving northwest over the central Arabian Sea. The image was taken at 6:23 a.m. local time (03:23 UTC) on June 4, 2007, when Gonu was a Category 4 storm. It shows the horizontal distribution of rain intensity looking down on the storm. The distribution of rain within the storm reveals the storm's structure, and in this case, Gonu displays all of the tell-tale signs of a potent storm. Not only did Gonu have a complete, well-formed, symmetrical eye surrounded by an intense eyewall (innermost red ring), this inner eyewall was surrounded by a concentric outer eyewall (outermost red and green ring). This double eyewall structure only occurs in very intense storms. Eventually the outer eyewall will contract and replace the inner eyewall, a process known as eyewall replacement. The image was made with data from several sensors on the TRMM satellite. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. Several hours after this image was taken, Gonu reached Category 5 intensity, the very peak of possible storm strengths. The system remained in this high state through the day, then began weakening during the night of June 4 as it continued to approach the coast of Oman. The center remained just offshore of the northeast coast of Oman as a Category 1 storm before turning northward towards Iran, where it was expected to make landfall as a tropical storm, according to forecasts made on June 6, 2007. The TRMM satellite was placed into service in November 1997. From its low-earth orbit, TRMM provides valuable images and information on storm systems around the tropics using a combination of passive microwave and active radar sensors, including the first precipitation radar in space. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. NASA image produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Typhoon Fitow
Title Typhoon Fitow
Description Typhoon Fitow moved gradually across the western Pacific in early September 2007, drawing closer to Japan and gaining strength. Forecasters were calling for the storm to continue on its track toward Honshu and make landfall on the island on September 6. This image shows clouds and rainfall associated with Typhoon Fitow at 6:25 a.m. local time on September 5 (21:51 UTC on September 4). At this time, the storm was a Category 2 [ http://www.nhc.noaa.gov/aboutsshs.shtml ] typhoon. The data come from the Tropical Rainfall Measuring Mission (TRMM) [ http://trmm.gsfc.nasa.gov/ ] satellite. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer swath come from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. A well-defined eye (dark center) marks the center of Fitow. The eye was surrounded by a band of intense rain, scattered locations within the eyewall (ring of clouds surrounding the eye) and the inner spiral arms also showed heavy rain (green arcs and red patches indicate moderate to heavy rain). The sharp curvature of these rain features means that Fitow's circulation was well developed, though the bands of clouds were not as tightly wound as they would be in a much stronger storm. The eyewall was not a solid wall of intense rain as it would likely be in a super typhoon (Category 4 and 5). At the time of this image, Fitow's maximum sustained winds were estimated at 140 kilometers per hour (85 miles per hour) according to the Joint Typhoon Warning Center. [ https://metocph.nmci.navy.mil/jtwc.php ] The TRMM satellite was placed into service in November 1997. From its low-earth orbit, TRMM provides valuable images and information on storm systems around the tropics using a combination of passive microwave and active radar sensors, including the first precipitation radar in space. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Image produced by Hal Pierce (SSAI/NASA GSFC).
Typhoon Usagi
Title Typhoon Usagi
Description Typhoon Usagi gathered strength as it moved over the West Pacific on a course for southern Japan in late July 2007. The storm was a well-organized, Category 2 storm when the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite captured these images on July 31, 2007. The top image shows the horizontal distribution of rain intensity looking down on the storm. Dark red circles of intense rain spiral out from a small, defined eye (dark center), with the largest area of intense rain on the west side of the storm. The storm's organization is evident in its symmetry: concentric rain bands surround the center. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). The lower image shows a three-dimensional view of Usagi at the same time. Areas of intense rain are associated with towering clouds known as convective towers. As water vapor rises, it cools and condenses into rain, releasing heat. It is this heat that feeds the storm. The higher water vapor rises before cooling, the more intense the storm tends to be. In this image, two tall towers (in red) border on the eye, indicating that Usagi is likely to continue to intensify as the towers release heat into the storm's core. Behind these is a partial ring of towering clouds that could be the beginning of an outer eyewall. At the time that TRMM captured these images, Usagi's sustained winds were estimated at 167 kilometers per hour (90 knots or 104 miles per hour). Soon after, Usagi was upgraded to a Category 3 cyclone with sustained winds estimated at 194 km/hr (105 knots or 121 mph). Usagi was expected to strengthen even further before possibly making landfall in southern Japan. The Tropical Rainfall Measuring Mission satellite was placed into low-Earth orbit in November 1997 with the primary mission of measuring rainfall from space, however, it has also served as a valuable platform for monitoring tropical cyclones, especially over remote parts of the open ocean. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Typhoon Usagi
Title Typhoon Usagi
Description Typhoon Usagi gathered strength as it moved over the West Pacific on a course for southern Japan in late July 2007. The storm was a well-organized, Category 2 storm when the Tropical Rainfall Measuring Mission (TRMM [ http://trmm.gsfc.nasa.gov/ ]) satellite captured these images on July 31, 2007. The top image shows the horizontal distribution of rain intensity looking down on the storm. Dark red circles of intense rain spiral out from a small, defined eye (dark center), with the largest area of intense rain on the west side of the storm. The storm's organization is evident in its symmetry: concentric rain bands surround the center. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). The lower image shows a three-dimensional view of Usagi at the same time. Areas of intense rain are associated with towering clouds known as convective towers. As water vapor rises, it cools and condenses into rain, releasing heat. It is this heat that feeds the storm. The higher water vapor rises before cooling, the more intense the storm tends to be. In this image, two tall towers (in red) border on the eye, indicating that Usagi is likely to continue to intensify as the towers release heat into the storm's core. Behind these is a partial ring of towering clouds that could be the beginning of an outer eyewall. At the time that TRMM captured these images, Usagi's sustained winds were estimated at 167 kilometers per hour (90 knots or 104 miles per hour). Soon after, Usagi was upgraded to a Category 3 cyclone with sustained winds estimated at 194 km/hr (105 knots or 121 mph). Usagi was expected to strengthen even further before possibly making landfall in southern Japan. The Tropical Rainfall Measuring Mission satellite was placed into low-Earth orbit in November 1997 with the primary mission of measuring rainfall from space, however, it has also served as a valuable platform for monitoring tropical cyclones, especially over remote parts of the open ocean. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Mars Rovers Battle Severe Du …
title Mars Rovers Battle Severe Dust Storm
Description Since late June 2007, Mars has been having a series of regional dust storms. The dust raised by these individual storms has obscured most of the planet over the past few weeks. The two maps shown here are mosaics of images acquired by the Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) on two days separated by about 3 and a half weeks. The first, on 22 June, shows that there was a dust storm occurring near the east end of the Valles Marineris trough system (left of the label for "Opportunity" in the map). This was the first in the series of storms. The second mosaic shows how Mars appeared on 17 July, after dust was lofted high into the atmosphere by several regional storms and countless smaller, local dust storms. Each map was constructed from 13 pole-to-pole image swaths at red, green, and blue wavelengths acquired by the MRO MARCI. The maps are simple cylindrical projections, with north at the top and south at the bottom. Each image swath was acquired at about 3 p.m. local time on Mars over the course of 13 orbits. The black gaps occur in the MARCI data at places where the MRO spacecraft was slewed east or west to point its instruments at a specific target of scientific interest. The north polar region is not shown because winter began on 4 July and the north polar region is in wintertime darkness. Key features labeled on the maps include the Tharsis Montes and Olympus Mons volcanoes, the Hellas impact basin, Noachis Terra, Sinus Meridiani, and the two Mars Exploration Rover (MER) landing sites, Opportunity and Spirit. The dust storms, and the planet-encircling dust veil they generated, has greatly reduced the amount of sunlight available to run the two solar-powered rovers., This sequence of Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) daily mosaics shows some of the dust storm activity that occurred near the Mars Exploration Rover (MER) Opportunity landing site between 21 June 2007 and 18 July 2007. The Opportunity rover is located near the martian prime meridian and equator. The top and middle rows of images show the first six days of dust storm activity near the rover site as dust advanced from the west to the south and passed south of the rover over the course of a week. By the end of that first week, storm activity strengthened and continued to move east, eventually passing over nearly half of the martian southern hemisphere. Other storms spawned by this atmospheric disturbance affected the MER Spirit rover on the other side of the planet, while new storms developed, approached, and affected Opportunity. The bottom three images show dust activity over the MER Opportunity site on 3, 14, and 18 July. By 19 July, most of the martian surface was obscured by the dust lofted from these storms. As with previous large dust-raising events on Mars, once the active storms die down, many weeks to months will pass before the dust settles out and the atmosphere clears. The white circle indicates the location of the Opportunity landing site, the black gaps are caused by slewing the spacecraft east or west to image specific science targets, and north in each picture is toward the top, west is to the left. More Images and Animations:Mars Exploration Rovers [ http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20070720a.html ] | MARCI Images [ http://www.msss.com/msss_images/2007/07/19/index.html ]Related Videos [ http://mars.jpl.nasa.gov/mro/gallery/video/index.html#20070720 ] Credit: NASA/JPL/Malin Space Science Systems
Hurricane Dean: Natural Haza …
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima …
Dean_TRM_2007227
mediatype IMAGE
mediatype image
date 2007-08-15
creator NASA -- NASA Image Of The Day
identifier Dean_TRM_2007227
1 2 3
1-50 of 115