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The View from Within AU Micr
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| Title |
The View from Within AU Microscopii's Disk |
| Description |
This is an artist's impression of the view from the vicinity of a hypothetical terrestrial planet and moon orbiting the red dwarf star AU Microscopii. The relatively newborn 12 million year-old star is surrounded by a very dusty disk of debris from the collision of comets, asteroids, and planetissimals swirling around the young star. Though no planets have been discovered around the star, the disk is strong circumstantial evidence for planets. Not only is it dusty, but also it is warped, possibly by the pull of one or more planets. In this view the glow of starlight reflecting off the disk creates a broad lane across the sky because the planet is in the disk's plane. Similarly, from Earth we see light reflected from interplanetary dust as the zodiacal light (though it is 1/10,000th as dusty as the AU Microcsopii disk). The star AU Microscopiii is 32 light-years from Earth. From this distance, familiar constellations are still recognizable. In the background, the Beehive cluster in Cancer the Crab is seen. Our Sun appears as a bright star in Cancer. |
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Spitzer and Hubble Capture E
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| Title |
Spitzer and Hubble Capture Evolving Planetary Systems |
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Three Years of Saturn
| Title |
Three Years of Saturn |
| Explanation |
Using an image recorded just last month as a base, this composite illustration tracks the motion of bright Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap070406.html ] as it wanders through planet Earth's night sky [ http://soc.jpl.nasa.gov/viewing.cfm ]. Starting at the upper right, Saturn's position is shown about every two weeks beginning in August 2005 and projected through September 2008. Over the three year period, Saturn actually appears to reverse its general eastward (leftward) drift, tracing out three flattened curves. The periodic backwards or retrograde motion [ http://antwrp.gsfc.nasa.gov/apod/ap060422.html ] with respect to the background stars is a reflection of the motion of the Earth itself. Retrograde motion [ http://www.lasalle.edu/~smithsc/Astronomy/ retrograd.html ] can be seen each time Earth overtakes and laps planets orbiting farther from the Sun, the Earth moving more rapidly through its own closer-in [ http://csep10.phys.utk.edu/astr161/lect/retrograde/ copernican.html ] orbit. The Beehive [ http://antwrp.gsfc.nasa.gov/apod/ap060128.html ] star cluster in Cancer lies near the track at the upper right. Stars along the "backward question mark" at the head of Leo [ http://stardate.org/nightsky/constellations/leo.html ] are in the left half of the frame. Saturn's position this month [ http://skytonight.com/observing/home/April_podcast.html ] is near the right hand limit of the middle curve. Click on the picture to download and view the gif animation. |
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Star Cluster Messier 67
| Title |
Star Cluster Messier 67 |
| Explanation |
Gathered [ http://www.seasky.org/cosmic/sky7a06.html ] at the center of this sharp skyview are the stars of Messier 67 [ http://www.seds.org/messier/m/m067.html ], one of the oldest known open star clusters [ http://en.wikipedia.org/wiki/Open_cluster ]. In fact, though open star clusters are usually much younger, the stars of M67 [ http://www.noao.edu/outreach/press/9907.html ] are likely around 4 billion years old, about the same age and with about the same elemental abundances as the Sun. Open clusters are almost always younger [ http://antwrp.gsfc.nasa.gov/apod/ap051118.html ] because they are dispersed over time as they encounter other stars, interstellar clouds, and experience gravitational tides while orbiting [ http://hypertextbook.com/facts/2002/StacyLeong.shtml ] the center of our galaxy. Still, M67 contains over 500 stars or so and lies some 2,800 light-years away in the constellation Cancer [ http://hawastsoc.org/deepsky/cnc/index.html ]. At that estimated distance, M67 would be about 12 light-years across. |
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55 Cancri: Familiar Planet D
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| Title |
55 Cancri: Familiar Planet Discovered |
| Explanation |
Is our Solar System [ http://www.nineplanets.org/overview.html ] unique? The discovery of a Jupiter [ http://www.nineplanets.org/jupiter.html ]-like planet in a Jupiter-like orbit around nearby Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ]-like star 55 Cancri [ http://www.jtwinc.com/Extrasolar/55Can_Star.html ], announced [ http://www.jpl.nasa.gov/releases/2002/release_2002_133.html ] yesterday, gives a new indication that planetary systems [ http://exoplanets.org/exoplanets_pub.html ] similar to our Solar System [ http://space.jpl.nasa.gov/ ] likely exist elsewhere. The planet, discovered by G. Marcy [ http://astro.berkeley.edu/~gmarcy/ ] (UC Berkeley [ http://astron.berkeley.edu/ ]) and collaborators, is one of two new planets found around 55 Cancri [ http://exoplanets.org/esp/55cnc/55cnc.shtml ] -- in 1997 a Jupiter-massed planet was found orbiting very close in. The finding involved noting subtle changes in the speed [ http://exoplanets.org/doppframe.html ] of the star caused by its orbiting planets. The above drawing depicts what this planet might look like, complete with a hypothetical moon. The star 55 Cancri [ http://www.astro.uiuc.edu/~kaler/sow/55cnc.html ], only 40 light-years distant, is visible [ http://irtf.ifa.hawaii.edu/Science/GalleryOfImages/55cancri.html ] with binoculars [ http://www.birdwatching.com/optics/binoculars1.html ] towards the constellation [ http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html ] of Cancer [ http://www.astronomical.org/constellations/cnc.html ]. |
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Jupiter, Moons and Bees
| Title |
Jupiter, Moons and Bees |
| Explanation |
Rising before the Sun on September 4, Jupiter and an old cresent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ] gathered in the dim constellation of Cancer [ http://www.coldwater.k12.mi.us/lms/planetarium/myth/ cancer.html ]. Watching from a hillside near Austin, Texas, planet Earth [ http://earthobservatory.nasa.gov/ ], astrophotographer Russell Croman recorded this view [ http://www.rc-astro.com/solar_system/moon/moonbees.html ] of their passing as clouds gracefully dimmed the brilliant moonlight. Earthshine illuminates [ http://www.amnh.org/exhibitions/codex/2A2r.html ] the lunar night side and on close inspection, bright Jupiter at the lower right appears tightly flanked [ http://antwrp.gsfc.nasa.gov/apod/ap980513.html ] by its own four large Galilean moons [ http://www.jpl.nasa.gov/galileo/ganymede/ discovery.html ]. Next to Jupiter lies a loose swarm of stars just below the clouds. The stars are the brighter members of the nearby star cluster M44, popularly known as the Beehive cluster [ http://antwrp.gsfc.nasa.gov/apod/ap980803.html ]. Croman's remarkable digital image has been processed only slightly to improve the visibility of the earthshine region and Jupiter's moons [ http://antwrp.gsfc.nasa.gov/apod/ap001118.html ]. |
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An Inner Neptune for 55 Canc
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| Title |
An Inner Neptune for 55 Cancri |
| Explanation |
Is our Solar System [ http://www.nineplanets.org/overview.html ] unique? The discovery [ http://arXiv.org/abs/astro-ph/0408585 ] of a Neptune [ http://www.nineplanets.org/neptune.html ]-mass planet in an sub-Mercury orbit around nearby Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ]-like star 55 Cancri [ http://antwrp.gsfc.nasa.gov/apod/ap020614.html ], announced [ http://planetquest.jpl.nasa.gov/index.html ] yesterday along with the discovery of other similar systems, gives a new indication that planetary systems [ http://exoplanets.org/exoplanets_pub.html ] as complex as our own Solar System [ http://space.jpl.nasa.gov/ ] likely exist elsewhere. The planet, discovered [ http://mcdonaldobservatory.org/news/releases/2004/0831.html ] in data from the Hobby-Eberly telescope [ http://www.as.utexas.edu/mcdonald/het/het.html ] in Texas, the Lick Observatory [ http://www.ucolick.org/ ] in California, and the orbiting Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ], is one of four planets now known to orbit 55 Cancri [ http://exoplanets.org/esp/55cnc/55cnc.shtml ] -- the others being similar in mass to Jupiter. The finding involved noting subtle changes in the speed [ http://exoplanets.org/doppframe.html ] of the star caused by its orbiting planets. The above drawing [ http://planetquest.jpl.nasa.gov/news/ssu_images.html ] depicts what this planet might look like, assuming a mass similar to Neptune [ http://antwrp.gsfc.nasa.gov/apod/neptune.html ], but a composition similar [ http://www.solstation.com/stars/4planets.htm ] to Earth. The star 55 Cancri [ http://www.astro.uiuc.edu/~kaler/sow/55cnc.html ], only 40 light-years distant, is visible [ http://irtfweb.ifa.hawaii.edu/Science/GalleryOfImages/55cancri.html ] with binoculars [ http://www.birdwatching.com/optics/binoculars1.html ] towards the constellation [ http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html ] of Cancer [ http://www.astronomical.org/portal/modules/wfsection/article.php?articleid=12 ]. |
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Saturn in the Hive
| Title |
Saturn in the Hive |
| Explanation |
If you can find Saturn [ http://www.spaceweather.com/images2006/27jan06/ skymap_north.gif ] in tonight's sky, then you can also find M44 [ http://www.seds.org/messier/m/m044.html ], popularly known as the Beehive [ http://antwrp.gsfc.nasa.gov/apod/ap020925.html ] star cluster. In fact, with a pair of binoculars most casual skygazers should find it fairly easy to zero in on this celestial scene [ http://skyandtelescope.com/observing/ataglance/ article_110_1.asp ]. Saturn is at opposition [ http://saturn.jpl.nasa.gov/multimedia/images/ image-details.cfm?imageID=1972 ] - opposite the Sun in Earth's sky - so, the bright planet rises in the east at sunset and is visible throughout the night. Near the stationary part [ http://www.scienceu.com/observatory/articles/retro/ retro.html ] of its wandering path through the heavens, Saturn will obligingly linger for a while in the vicinity of M44 in the relatively faint constellation Cancer [ http://www.coldwater.k12.mi.us/lms/planetarium/myth/ cancer.html ]. Seen here in a photograph from January 25, Saturn (lower right) is strongly overexposed with the stars of M44 swarming above and to the left. The picture approximately corresponds to the view [ http://www.visualdeepsky.org/netastrocatalog/ msg00123.html ] when looking through a typical pair of binoculars. Saturn is [ http://nssdc.gsfc.nasa.gov/planetary/planets/ saturnpage.html ] about 64 light-minutes from our fair planet while M44, one of the closest star clusters, is around 600 light-years away. |
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Red Plankton in the Arabian
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nasa, nasaimageofthedaygalle
…
In the Arabian Sea, sunlight
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PIA04369
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2004-10-02 |
| creator |
NASA -- Image courtesy NASA/GSFC/LaRC/JPL, www-misr.jpl.nasa.gov/ MISR Team. Text by Clare Averill (Raytheon/JPL) and Dr. Patria Viva F. Banzon (University of Miami). |
| identifier |
PIA04369 |
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Remembering Yoram Kaufman: I
…
nasa, nasaimageofthedaygalle
…
Teams for the MISR and CERES
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yoram_memorial
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-05-26 |
| creator |
NASA -- Photographs and image courtesy NASA |
| identifier |
yoram_memorial |
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Red Plankton in the Arabian
…
PIA04369
Sol (our sun)
Multi-angle Imaging SpectroR
…
| Title |
Red Plankton in the Arabian Sea |
| Original Caption Released with Image |
. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 25483. The still image panels cover an area of about 240 kilometers x 290 kilometers, and utilize Local Mode data from within blocks 71 to 73 and within World Reference System-2 path 155. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology., In the Arabian Sea, sunlight and nutrients has fueled a startling occurrence of colorful phytoplankton and bacterial assemblages, which is captured in these natural color images from NASA's Multi-angle Imaging SpectroRadiometer (MISR). Several areas exhibit an unmistakably reddish hue, particularly in the upper portion of the images. The image set is centered along the Tropic of Cancer, about 400 kilometers east of Muscat, Oman, and was acquired on October 2, 2004. A view from MISR's nadir (directly downward viewing) camera is provided on the left, while the two smaller images at the upper and lower right are from MISR's 60-degree forward and backward pointing cameras, respectively. The Arabian Sea is an unusual part of the world's oceans because it is surrounded by land masses from three sides, and light levels in the region are strongly influenced by cloud cover generated by the Indian monsoons. Phytoplankton concentrations in the Arabian Sea tend to be highest during September and October, towards the end of the summer monsoon. The offshore drift of surface waters and their replacement by deeper, nutrient-rich waters means that the Arabian Sea is very productive, but such fertilization also sometimes results in copious phytoplankton production and oxygen depletion of the subsurface waters. Although red phytoplankton fluorescences have been associated with the low oxygen concentrations in the intermediate and deep waters of the Arabian Sea, the red pigment in this scene may instead be related to the dynamic processes of plankton grazing and decomposition. Multiple observation angles allow the color of surface ocean waters to be studied in greater detail, and provides a method to observe regions that can not be examined by satellite instruments that view nadir only, in cases where the nadir view is affected by sun glint. In this case, the ocean color in the lower right-hand corner is discernible at 60-degrees backward but not at nadir. Multiple angles also enable the observation of ship and cloud motion. The movement of several ships across the scene is illustrated in an animation. The oblique imagery used in this image set is part of the Local Mode data acquired during the Unified Aerosol Experiment United Arab Emirates (UAE2) field campaign |
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