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Egypt Sand Dunes L, C & X ba
…
This three-frequency space r
…
2/15/96
| Date |
2/15/96 |
| Description |
This three-frequency space radar image of west central Egypt shows detailed patterns of eroded sedimentary rock formations emerging through a vast sea of sand dunes. The broad black bands that dominate the image are thick ridges of sand known as longitudinal dunes. In this region of the Sahara, a single ridge may be as long as several hundred kilometers. Thin red lines within the black bands are bright reflections from the steep crests of the sand ridges. Between the dunes are colorful patterns of rock outcrops that are either exposed at the surface or covered with very thin layers of sand that the radar "sees" through. Some of the rock areas are fringed in red, indicating that only the long wavelength L-band signal is penetrating the sand to image the rock surface. Most of the other color variations are due to different roughness textures of the rock surface, which are caused by different types of rocks, such as limestone, shale and sandstone. Scientists are using the penetrating capabilities of radar imaging in desert areas to study structural geology, mineral exploration, ancient climates, water resources and archaeology. This image is 55 kilometers by 31.7 kilometers (34.1 miles by 19.6 miles) and is centered at 26.2 degrees north latitude, 26.9 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received, green is C-band, horizontally transmitted and received, and blue is X-band, vertically transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 17, 1994 onboard the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. ##### |
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Safsaf Oasis, Egypt L, C & X
…
This three-frequency space r
…
2/29/96
| Date |
2/29/96 |
| Description |
This three-frequency space radar image of south-central Egypt demonstrates the unique capability of imaging radar to penetrate thin sand cover in arid regions to reveal hidden details below the surface. Nearly all of the structures seen in this image are invisible to the naked eye and to conventional optical satellite sensors. Features appear in various colors because the three separate radar wavelengths are able to penetrate the sand to different depths. Areas that appear red or orange are places that can be seen only by the longest wavelength, L-band, and they are the deepest of the buried structures. Field studies in this area indicate L-band can penetrate as much as 2 meters (6.5 feet) of very dry sand to image buried rock structures. Ancient drainage channels at the bottom of the image are filled with sand more than 2 meters (6.5 feet) thick and therefore appear dark because the radar waves cannot penetrate them. The fractured orange areas at the top of the image and the blue circular structures in the center of the image are granitic areas that may contain mineral ore deposits. Scientists are using the penetrating capabilities of radar imaging in desert areas in studies of structural geology, mineral exploration, ancient climates, water resources and archaeology. This image is 51.9 kilometers by 30.2 kilometers (32.2 miles by 18.7 miles) and is centered at 22.7 degrees north latitude, 29.3 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received, green is C-band, horizontally transmitted and received, and blue is X-band, vertically transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 16, 1994, on board the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program. ##### |
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Safsaf, L&C
This is a false-color image
…
4/16/94
| Date |
4/16/94 |
| Description |
This is a false-color image of the uninhabited Safsaf Oasis in southern Egypt near the Egypt/Sudan border. It was produced from data obtained from the L-band and C-band radars that are part of the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour on April 9, 1994. The image is centered at 22 degree north latitude, 29 degrees east longitude. It shows detailed structures of bedrock, the dark blue sinuous lines are braided channels that occupy part of an old broad river valley. On the ground and in optical photographs, this big valley and the channels in it are invisible because they are entirely covered by windblown sand. Some of these same channels were observed in SIR-A images in 1981. It is hypothesized that the large valley was carved by one of several ancient predecessor rivers that crossed this part of North Africa, flowing westward, tens of millions of years before the Nile River existed. The Nile flows north about 300 kilometers (200 miles) to the east. The small channels are younger, and probably formed during relatively wet climatic periods within the past few hundred thousand years. This image shows that the channels are in a river valley located in an area where U.S. Geological Survey geologists and archeologists discovered an unsual concentration of handaxes (stone tools) used by Early Man (Homo erectus) hundreds of thousands of years ago. The image clearly shows that in wetter times, the valley would have supported game animals and vegetation. Today, as a result of climate change,the area in uninhabited and lacks water except for a few scattered oases. This color composite image was produced from C-band and L-band horizontal polarization images. The C- band image was assigned red, the L-band (HH) polarization image is shown in green, and the ratio of these two images (LHH/CHH) appears in blue. The primary and composite colors on the image indicate the degree to which the C-band, H-band, their ratio -- or some combination of all three -- respond to the roughness of the radar backscattering surface. Using this coloring scheme, areas that appear bright at both L-band and C-band are colored yellow, while areas that appear brighter at L-band than C-band appear more blue. Detailed analysis of this scene indicates that the separate C-band and L-band images used to produce this color composite have a very similar overall appearance. This suggests that the C- band and the L-band signals are both easily penetrating the thin 1- to 12-centimeter (0.5- to 5-inch) "average" surface cover of loose windblown sand, and are commonly "seeing" similar interfaces just below that cover. This radar interface may be at the scattered rocky outcrops on the ground surface, but is more likely to be the shallow underlying surfaces of river gravel or bedrock, which are generally covered by only a few inches of windblown sand. Virtually everything visible on this radar composite image cannot be seen, either when standing on the ground or when viewing photographs or satellite images such as the United States' Landsat or the French SPOT satellite. ----- Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI). |
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Red Sea Dust Storm
| title |
Red Sea Dust Storm |
| date |
05.13.2005 |
| description |
A thick snake of tan dust slithers across Egypt, Saudi Arabia, and the Red Sea in this dramatic true-color image acquired by the Aqua MODIS instrument on May 13, 2005. The dust is so thick that it is completely opaque for well over 700 miles across its south-moving front, from the border of Iraq, across the Arabian Desert of Saudi Arabia and Egypt, and all the way past the green ribbon of the Nile to the Libyan Desert in western Egypt. |
|
GPM Nile River Animation
| Title |
GPM Nile River Animation |
| Abstract |
Global Precipitation Measurement (GPM) mission is to improve ongoing efforts to predict climate, improve the accuracy of weather and precipitation forecasts, and to provide more frequent and complete sampling of the Earth's precipitation. |
| Completed |
2003-07-01 |
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African Dust over the Red Se
…
| Title |
African Dust over the Red Sea |
| Description |
Blowing dust swirled over (top left to bottom) Egypt, Sudan, and Eritrea, and the Red Sea (center) on July 16, 2004. Summertime dust storms such as these have a significant cooling influence on regional temperatures there and to a lesser extent on temperatures across the Northern Hemisphere. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA?s Terra satellite captured this scene. NASA image courtesy Jacques Descloitres, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at GSFC |
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Floods in Sudan
| Title |
Floods in Sudan |
| Description |
Though flooding occurs every year in the African country of Sudan, 2007 brought unusually extreme floods that affected at least 400,000 people as of August 29, reported the United Nations. [ http://www.reliefweb.int/rw/rwb.nsf/db900sid/YSAR-76JMJK?OpenDocument&rc=1&emid=FL-2007-000093-SDN ] Apart from destroying buildings, crops, and land, the swollen rivers and pools of standing water increase the risk of water-borne disease such as cholera, acute watery diarrhea, and malaria, said the United Nations. This photo-like image, captured by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on August 29, 2007, shows flooding around the capital city of Khartoum, the tan-gray area nestled between the converging Blue and White Nile Rivers. To the south, sunlight reflecting off the surface of the water has turned the Blue Nile River silvery white, making it stand out from the surrounding land. Brilliant flecks of silver in the landscape between the two rivers are created by light reflecting off standing water or some other bright surface. The sunlight also highlights the intricate network of canals that run like arteries through squares of green agriculture. In the west, the White Nile River paints a wide, white-brown ribbon down the landscape. The river is several times wider than it is during the dry season, as a comparison with a cloud-free image [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?NAfrica_2_07/2007172/NAfrica_2_07.2007172.terra ] from June 2007 reveals. (The area shown here is in the lower-left corner of the image.) As long as human civilization has clung to the fertile banks of the Nile River, the yearly flood cycle has regulated life. Today, the river is tamed by dams in southern Egypt so that only its upper reaches and its tributaries, the White and Blue Nile Rivers, still rise and fall with the annual rainy season in the Ethiopian highlands. Most of the flood water on the Nile typically comes from the Blue Nile River, the tributary that flows out of Ethiopia, but in this image, it is the White Nile River that appears most flooded. The floods on the White Nile most often arise when high water on the Blue Nile blocks the flow of water from the White Nile into the Nile River. Unable to continue flowing freely downstream, the White Nile pools behind the convergence point, as shown here. Another sign of flooding in the image is the addition of green to the land. Even beyond the irrigated land between the two rivers, the arid orange landscape is brushed with green where seasonal rivers have nourished new plants. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
Gebel Edmonstone, Egypt
| Title |
Gebel Edmonstone, Egypt |
| Description |
Gebel (or Mount) Edmonstone is a flat-topped mesa located near the Dahkla Oasis south of Cairo, Egypt. The Oasis is a historically important meeting place of several trade routes connecting different regions of Egypt and Sudan. Gebel Edmonstone is a remnant of an eroding scarp that extends for over 200 kilometers (125 miles) east-southeast to west-northwest (visible in the upper left corner of the image). The flat caprock of both the scarp and Mount Edmonstone is chalky limestone underlain by fossil-bearing shale and fine-grained sedimentary rocks. Digital astronaut photographs can be processed in similar fashion to other multispectral remotely sensed data to maximize information content. This astronaut photograph has been "stretched" to enhance color variations in the various rock and soil units. The color variations reflect differences in composition (or weathering) of the various rock units. The limestone unit capping Gebel Edmonstone and the adjacent scarp ranges from white to gray in color, while the underlaying fine-grained sedimentary layers are blue-gray. Hillslope pathways for sediment movement downslope are clearly visible as brown to tan streamers originating from Gebel Edmonstone. Barchan dune fields are also visible in this color-enhanced image, and are distinct due to their mineralogical composition. Evaporite deposits are bright white, while vegetated portions of the Oasis—mostly agricultural fields—are dark blue-black. This additional information obtained from image enhancement can be used for geologic mapping and investigation of surficial processes operating in the region. Astronaut photograph ISS009-E-12441 [ http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS009&roll=E&frame=12441 ] was acquired June 18, 2004 with a Kodak 760C digital camera with a 400 mm lens and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center. The International Space Station Program [ http://spaceflight.nasa.gov/home/index.html ] supports the laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. [ http://eol.jsc.nasa.gov/ ] |
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Dust and Smoke over the Medi
…
| Title |
Dust and Smoke over the Mediterranean |
| Description |
On October 17, 2006, the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured dust and smoke blowing northward over the Mediterranean Sea. The dust came from a dust storm along the border between Libya and Egypt. The smoke came from fires in the Nile Delta, hundreds of kilometers to the east. In this image, multiple plumes of dust blow off the coastlines of Libya and Egypt. The thickest plume originates just east of the border between the two countries, and two smaller plumes off Egypt merge over the Mediterranean. Overhead, rows of small, bright white clouds cast their shadows onto the dust. Just south of the coast, a sand sea crosses the border between Libya and Egypt, and this sand sea may have been the source of at least some of the dust. The Nile Delta stands out from the arid landscape of the Sahara, but the same vegetation that gives the delta its lush green appearance can also catch fire. This image shows a series of red dots called hotspots, where MODIS has detected surface temperatures much hotter than their surroundings. Faint wisps of smoke from the fires blow northward toward the Mediterranean, dissipating not far beyond the shore. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Dust Over East Africa and Is
…
| Title |
Dust Over East Africa and Israel |
| Description |
This scene shows a large cloud of dust blowing from northeastern Africa across Egypt, the Sinai Peninsula, over Israel and into the Middle East region on March 19, 2002. It is actually a composite image from two data sources. The true-color image of the surface was made using Moderate-resolution Imaging Spectroradiometer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://modarch.gsfc.nasa.gov/ ] (MODIS) data. A false-color representation of Total Ozone Mapping Spectrometer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://toms.gsfc.nasa.gov/ ] (TOMS) measurements of aerosol index was overlain to show the extent of the dust cloud. The aerosol index is a measure of how much ultraviolet light is absorbed by the aerosol particles within the atmosphere, and is approximately equal to the optical depth. Red areas indicate high aerosol index values and correspond to the most dense portions of the dust cloud. Yellows and greens are moderately high values. The TOMS reflectivity data shows that there were relatively few clouds in the area that day. While TOMS cannot see through clouds, the aerosol index value for clouds is zero, so that any small clouds in the region would be ignored, while still detecting the aerosols between and above the clouds. Image courtesy Jay Herman, TOMS Aerosol/UV Project Principal Investigator, NASA GSFC |
|
Dust over Greece
| Title |
Dust over Greece |
| Description |
Powerful winds pulled a thick band of desert dust from Egypt and Libya over the Mediterranean Sea on April 17, 2005. The dust is so thick that Crete is completely obscured from view, and the ground of Greece is barely visible. African dust frequently blows over the Mediterranean in the spring, carrying tons of dust into Greece. This particular storm shrouded the country in a yellow haze that cancelled or delayed flights and halted sea transport, according to local news reports. The winds that produced this dust storm blew at an average of 75-89 kilometers per hour (47-55 mph) near the sea?s surface, and stronger winds prevailed higher in the atmosphere. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Aqua [ http://aqua.nasa.gov/ ] satellite captured this photo-like image of the storm. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. The image is available in additional resolutions. |
|
Dust over the Red Sea
| Title |
Dust over the Red Sea |
| Description |
A dust storm blew across the Red Sea on June 9, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Terra [ http://terra.nasa.gov/ ] satellite took this picture the same day. In this image, a dust plume partially obscures the view of the Red Sea, between Egypt in the west, and Saudi Arabia in the east. Extreme summer heat increases the likelihood of dust storms, and the sand seas of the Middle East produce many of the planet's dust plumes. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
|
Dust Plume off the Coast of
…
| Title |
Dust Plume off the Coast of Egypt |
| Description |
Dwarfing the Nile, a river of dust flowed out of the deserts of northern Egypt on May 19, 2007. As the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite passed overhead at 12:05 p.m. local time in Cairo, the sensor captured this image of the dust spreading northward over the Mediterranean Sea from the sandy deserts that span the country. At the margins of the plume, ribbons and ripples of dust are translucent, allowing a glimpse of the desert and water beneath, but in the center, the cloud is opaque, revealing nothing of the surface below. The part of north-central Egypt hidden by the dust plume is the Qattara Depression, the country's lowest point. Dipping down to 133 meters below sea level (436 feet), the depression is home to sandy deserts and dry lake beds that occasionally flood. The sand and fine, lake bed sediments are easily lofted into the air by strong winds that scour the area in late winter and early spring. In the eastern (right-hand) part of the image, the Nile River is lined by narrow ribbons of dull green vegetation. The fan-shaped delta is dotted with tan-colored spots, marking the location of cities and towns. The Nile Valley and Delta make up only a small fraction of the country's total land area, yet they support almost the entire population. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides this image in additional resolutions. [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2007139-0519/Egypt.A2007139.0905 ] The Earth Observatory also provides a 250-meter-resolution KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/May2007/Egypt.A2007139.0905.250m.kmz ] of this image for use with Google Earth. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
|
Dust Plume off the Coast of
…
| Title |
Dust Plume off the Coast of Northern Africa |
| Description |
Dust blew off the African coast and over the Mediterranean Sea on June 9, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite captured this image the same day. In this image, the opaque tan dust plume billows off the coast, along the Libya-Egypt border, in a shape vaguely resembling a giant inverted teardrop. Directly north of the dust plume lies the island of Kriti (Crete). North of that, much smaller islands dot the Aegean Sea. Pale streamers sweep southward from these islands, from a cause that appears unrelated to the dust plume. The streamers may be "wind shadows" on the ocean surface highlighted by sunglint that results from the Sun's light bouncing off the water's surface and into the satellite sensor. You can download a 250-meter-resolution KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/nafrica_tmo_2007160.kmz ] of the dust storm for use with Google Earth. [ http://earth.google.com/download-earth.html ] NASA image created by Jesse Allen, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
|
Dust Storm in North Africa
| Title |
Dust Storm in North Africa |
| Description |
One day after a dust storm in Algieria, Tunisia, and Libya, more dust swept off the north coast of Africa on December 15, 2005. This storm swept northward off the coasts of Libya and Egypt over the Mediterranean. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image the same day. In this image, a pale beige plume of dust merges with a swirling cloud formation over the sea. The dust dissipates toward the east, although distinct plumes can be seen off the coast of Egypt. To the east of the storm is Egypt's lush Nile Delta. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team at NASA GSFC |
|
Dust Storm in Northern Afric
…
| Title |
Dust Storm in Northern Africa |
| Description |
Dust still lingered over northern Africa on February 24, 2006, a day after a massive dust storm swept over Algeria, Tunisia, and Libya. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image on February 24. In this image, a cloud of dust several hundred kilometers across extends from Libya and Egypt over the Mediterranean Sea. Faint tendrils of dust reach as far to the east as Israel. Although the dust hides many land features in northern Africa, the lush, green Nile Delta still stands out from its surroundings. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
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Dust Storm in Northern Afric
…
| Title |
Dust Storm in Northern Africa |
| Description |
Dust remained in the air another day, two days after a major dust storm struck northern Africa on February 23, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard the Terra [ http://terra.nasa.gov/ ] satellite captured this image on February 25. By the time this image was acquired, the dust had moved toward the northeast over the Mediterranean Sea. In this image, a pale beige cloud of dust several hundred kilometers across extends northward from Egypt over the sea. The dust cloud also completely obscures the view of the Nile Delta, in contrast to the dust cloud the day before. The thick cloud of dust lies close to the ground. On the island of Cyprus, the Troödos Mountains, including the 1,951-meter-high (6,400-foot-high) summit of Mount Olympos, rise above the dust cloud. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
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Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
A dust storm blew off the north coast of Africa along the Libyan-Egyptian border on September 15, 2005. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image the same day. In this image, a dust storm fans out over the Mediterranean from the desert. In Egypt, two features stand out from the otherwise pale beige Saharan landscape. One is the Qattara Depression, the second-lowest region in Africa (after Lake Asal). The depression contains salty marshes, and at the bottom is a salt pan. The other feature is the green, fertile Nile Delta. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team at NASA GSFC |
|
Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
A dust storm swept off the coast of Egypt and over the Mediterranean Sea on January 23, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard the Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. This image shows a thin veil of dust moving in a counterclockwise direction and mixing with clouds over the sea. Although North Africa is the likely suspect, the exact source of dust can't be clearly discerned from this image. Even under a haze of aerosols, however, the lush Nile Delta clearly stands out from its arid surroundings as a green triangle. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the Goddard Earth Sciences DAAC. |
|
Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
A dust storm swept over Egypt on February 8, 2006, moving in a counterclockwise direction from the Sahara Desert toward the Mediterranean Sea. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard the Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. In this image, the dust appears as a pale beige swirl over the landscape, blurring many of the features on the ground. To the north of the dust are dense clouds hanging over the Mediterranean. This storm produced a dust cloud much thicker than the one observed on January 23, 2006 [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13320 ]. Unlike that dust storm, this one completely obscured the view of the Nile Delta, which usually stands out from its surroundings as a lush green triangle. According to news reports, a huge cargo ship blocked the Suez Canal on Wednesday after drifting into a bad position during the storm. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team at NASA GSFC |
|
Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
Several large, thick plumes of desert dust (brownish pixels) were blowing from Egypt and Libya northward over the Mediterranean Sea, on January 12, 2003. The Greek island of Crete is partially obscured by the dust in the upper lefthand corner of this scene. The island of Cyprus is in the upper righthand of this image, just to the east of the dust plume. This true-color image was acquired on Jan. 12 by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA?s Aqua satellite. The high-resolution image available here is 500 meters per pixel. Visit the MODIS Rapid Response Team, for a copy of this scene at MODIS? full resolution of 250 meters per pixel. Image courtesy Jacques Descloitres, MODIS Rapid Response Team, NASA GSFC |
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Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
A large plume of Saharan Desert dust (light brownish pixels) blew over Egypt northward and eastward over the Middle East, on February 3, 2003. In this scene, the dust plume appears particularly thick over the Red Sea (lower right), blowing eastward toward the Arabian Peninsula. This true-color image was acquired on February 3, 2003, by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA?s Terra satellite. The high-resolution image available here is 500 meters per pixel. Visit the MODIS Rapid Response Team, for a copy of this scene at MODIS? full resolution of 250 meters per pixel. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
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Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
A large plume of Saharan Desert dust (light brownish pixels) were blowing over Libya and Egypt northward over the Mediterranean Sea toward the Middle East, on February 2, 2003. The island of Cyprus is situated toward the upper righthand of this image, partially obscured by one particularly thick portion of the dust plume approaching Israel?s western shoreline. This true-color image was acquired on February 2, 2003, by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA?s Aqua satellite. The high-resolution image available here is 500 meters per pixel. Visit the MODIS Rapid Response Team, for a copy of this scene at MODIS? full resolution of 250 meters per pixel. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
This true-color image of Saharan Desert dust blowing northeastward from Libya and Egypt across the Mediterranean Sea was acquired on February 5, 2003, by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the OrbView-2 satellite. Image courtesy the SeaWiFS Project, [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://seawifs.gsfc.nasa.gov/SEAWIFS.html ] NASA/Goddard Space Flight Center, and ORBIMAGE |
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Dust Storm off Egypt
| Title |
Dust Storm off Egypt |
| Description |
*Dust Storm off Egypt* On Febuary 6, 2003, strong winds blew Saharan dust from Libya and Egypt out across the Mediterranean Sea. The plume can be seen in the above image acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua spacecraft. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Dust Storm over Eastern Medi
…
| Title |
Dust Storm over Eastern Mediterranean |
| Description |
A large plume of Saharan Desert dust (tan pixels) was blowing over Egypt and the Eastern Mediterranean on May 10, 2003. This true-color image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Aqua satellite. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS' maximum spatial resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Dust Storm over Libya
| Title |
Dust Storm over Libya |
| Description |
Saharan dust swept northward across Libya and northwestern Egypt toward the Mediterranean on February 23, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov ] satellite took this picture the same day. In this image, the semitransparent plume of dust covers most of Libya and part of Egypt. The dust also appears over Chad, with part of the plume covering a dark, rocky area near the lower left corner of the image. The dust storm did not likely originate in this region, but farther south. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
|
Dust Storm over Libya and Eg
…
| Title |
Dust Storm over Libya and Egypt |
| Description |
Dust continued to blow across northern Africa and the Mediterranean Sea on March 3, 2005. In this image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite, dust stretches northeastward from Libya and Egypt all the way to the island of Cyprus (upper right). NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the MODIS Rapid Response team. |
|
Dust Storm over Libya and Eg
…
| Title |
Dust Storm over Libya and Egypt |
| Description |
A thin sheet of dust blew northeastward from deserts in northern Africa and out across the Mediterranean Sea (upper right) on March 1, 2005. The orange-colored sands of eastern Algeria are thickly veiled with light-colored dust, which thins as it spreads more widely over Tunisia and Libya. The dust weaves both under and over clouds in different places over the Mediterranean. At the far right edge, the clouds appear bright white, and appear to be casting a shadow on the dust plume below them. At top center, dust appears to be above the clouds, giving them a dirty appearance. This image was made from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA?s Aqua [ http://aqua.nasa.gov ] satellite. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ], NASA-GSFC |
|
Dust Storm over Libya and Eg
…
| Title |
Dust Storm over Libya and Egypt |
| Description |
Ripples on the wind have created the intricate wave patterns seen in this thick plume of dust over Egypt and Libya. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image on February 28, 2005, just as a strong gust of wind pulled a streamer of dust out over the Mediterranean Sea. This dust storm started on February 28, and continued through at least March 2. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. The image is available in additional resolutions. |
|
Dust Storm Over Red Sea
| Title |
Dust Storm Over Red Sea |
| Description |
A great cloud of dust and sand hangs over the Red Sea (image center) in this image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite captured on August 20, 2003. The cloud of dust begins at the border of Egypt (top left) and Sudan (below) and stretches southward to Eritrea and eastward across the Red Sea to Saudi Arabia and Yemen. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS? maximum spatial resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Dust Storm over the Mediterr
…
| Title |
Dust Storm over the Mediterranean Sea |
| Description |
A dust storm, likely originating in the Sahara Desert, swept across the Mediterranean Sea on February 24, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov ] satellite took this picture the same day. In this image, the dust appears as an undulating swath of tan over the dark ocean water. The storm also clouds skies over Lebanon, Israel, the West Bank, Gaza, and Egypt. Even through a layer of dust, however, the Nile Delta still sports a lush green hue, in contrast to its largely arid surroundings. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
|
Dust storms out of Egypt
| Title |
Dust storms out of Egypt |
| Description |
For the second day in a row, dust blew out of the Great Sand Sea and other deserts in northern Egypt, veiling the green triangle of the Nile Delta with plumes of dust. A thick plume more than 100 kilometers wide crosses the Mediterranean Sea to the north, reaching the coast of Turkey (upper right). This image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite on January 30, 2005. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Dust storms out of Egypt
| Title |
Dust storms out of Egypt |
| Description |
The deep blue waters of the Mediterranean Sea were shrouded in dust from North African deserts on January 29, 2005. A dusty haze stretches across the center and top parts of the scene from the Gulf of Sirte (left center edge), past the Nile Delta (right of center), all the way to Turkey (top right). The Red Sea (lower right corner) appears to be dust free. Between the knob of land in Libya just east of the Gulf of Sirte and the green fan of the Nile Delta lies a large desert called the Great Sand Sea. Dust storms are a serious natural hazard in the region, particularly for aircraft. This image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Khartoum, Sudan
| Title |
Khartoum, Sudan |
| Description |
Sudan's capital city, Khartoum, translates as "Elephant's Trunk." The name describes the shape of the Nile where the Blue and the White Nile Rivers unite to form the single Nile River that flows northward into Egypt. This image shows the rivers near the end of the dry season. The White Nile (western branch) runs through Sudan from Uganda. The White Nile originates in equatorial regions, where rainfall occurs throughout the year, as a result, it runs at a nearly constant rate throughout the year. The Blue Nile, nearly dry this time of year, flows out of the Ethiopian highlands, where rainfall is more seasonal. The Blue Nile swells in the late summer and early fall with rains from the summer monsoons. The flow at these times can be so great that the volume is too much for the river's channel, causing the Nile to flow backward at the junction. In recent years, floods in Khartoum have occurred in August with heavy monsoon rainfall. (See more images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=5148 ] and Multi-angle Imaging SpectroRadiometer [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=5113 ] instruments) Khartoum is one of the largest Muslim cities in North Africa, but it has a fairly short history. Founded as a military outpost in 1821, a Sudanese flag has only flown over the city since 1956. Today, Khartoum is home to more than a million people, including many refugees, both from neighboring countries as well as from an ongoing civil war in southern Sudan. The city has a low profile, dominated by sprawling areas of small buildings that are supported by little infrastructure. Astronaut photograph ISS010-E-23451 [ http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS010&roll=E&frame=23451 ] was acquired April 7, 2005, with a Kodak 760C digital camera with a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center. The International Space Station Program [ http://spaceflight.nasa.gov/home/index.html ] supports the laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. [ http://eol.jsc.nasa.gov/ ] |
|
Lake Nasser, Egypt
| Title |
Lake Nasser, Egypt |
| Description |
One of the world's largest artificial lakes, Lake Nasser is named after the Egyptian President Gamal Abdul Nasser, who is largely responsible for the lake's creation. President Nasser decided to build the Aswan High Dam across the Nile, forming a lake approximately 550 kilometers (340 miles) long. In this astronaut photograph taken from the International Space Station, the water of Lake Nasser stands out from its surroundings due to sunglint. The Sun's light reflects off the water's surface and into the camera lens, giving Lake Nasser an iridescent sheen. Sunglint is a common phenomenon in satellite images as well as astronaut photographs. The Aswan High Dam, which created this massive lake, is the newer of two dams in the vicinity. The older of these dams is known as the Aswan Low Dam, or simply the Aswan Dam. Completed in 1902, the older dam had nearly overflowed by the middle of the 20th century, despite having been raised twice. Instead of raising it a third time, officials chose to build the Aswan High Dam upriver in the 1960s. The dam proved to be a mixed blessing, providing some residents with irrigation and drinking water, but forcing thousands of others to relocate to higher ground. The Aswan High Dam ultimately proved much more effective than its predecessor, so effective that the dam's construction spawned another massive effort. The ancient Egyptian temple of Abu Simbel lay in the path of the rising waters produced by the new dam. In the 1960s, the historical site was literally taken apart piece by piece and reassembled in a new place to avoid submersion. The Aswan High Dam has not, however, proven immune to overflowing. High levels of rainfall led to new lakes [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4437 ] in the region in the late 1990s. The name of Lake Nasser technically refers only to the portion of this lake in Egypt. The Sudanese prefer to call their portion of the lake Lake Nubia. Astronaut photograph ISS010-E-14618 [ http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS010&roll=E&frame=14618 ] was acquired January 23, 2005, with a Kodak 760C digital camera with a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center. The International Space Station Program [ http://spaceflight.nasa.gov/home/index.html ] supports the laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. [ http://eol.jsc.nasa.gov/ ] |
|
Saharan Dust over the Red Se
…
| Title |
Saharan Dust over the Red Sea |
| Description |
A thick plume of desert dust (tan colored) was blowing eastward out of southern Egypt and Sudan, and out over the Red Sea on September 1, 2004. The dust is so thick in many places that it completely blocks the view of the surface. This true-color scene was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua satellite. The high-resolution image available here is 250 meters per pixel. NASA image by Jesse Allen, Earth Observatory, using data courtesy MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] |
|
Severe Storm over the Red Se
…
| Title |
Severe Storm over the Red Sea |
| Description |
An Egyptian ferry carrying more than 1,300 people sank on February 2, 2006, in the northern Red Sea as strong storms swept across the region. While the exact cause of the disaster was not certain, the most likely reason was bad weather and high seas. At the time of the incident, a potent storm was advancing eastward over Egpyt and the western Mediterranean Sea. Out ahead of this advancing storm, strong southerly winds drew warm moist air up from the south. These conditions favour the development of severe storms. The Tropical Rainfall Measuring Mission (TRMM) satellite observed the storm at 04:20 UTC on February 3, 2006 (6:20 a.m. in Egypt), just a few hours after radar contact with the ferry was lost. The image shows the horizontal distribution of rain rates (top-down view) observed by the TRMM satellite. The image reveals that an intense thunderstorm complex had just come ashore on the Saudi Arabia coastline, after having crossed the northern Red Sea. The storm complex contained a sizeable area of heavy rain, with rates of 50 millimeters per hour (dark red areas). While not a direct measure of storm intensity, the heavy rain and the shape and orientation of the storm complex indicate that the storm was severe. In this image, rain rates in the center swath are from the TRMM Precipitation Radar, while rain rates in the outer swath are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. The TRMM satellite was launched into service in November of 1997. Designed to measure rainfall over the global tropics, TRMM is armed with both passive and active sensors, including the first and only precipitation radar in space. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. NASA images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC). |
|
Sharm El Sheik, Egypt
| Title |
Sharm El Sheik, Egypt |
| Description |
The Red Sea golf resort in Sharm El Sheik, Egypt, where President Clinton met with Israeli Prime Minister Ehud Barak and Palestinian Authority President Yasser Arafat, stands out against the desert landscape in this image acquired on August 25, 2000. This image of the southern tip of the Sinai Peninsula shows an area about 30 by 30 kilometers (19 by 19 miles) in the visible and near infrared wavelength region. Vegetation appears in red. The blue areas in the water at the top and bottom of the image are coral reefs. The airport is visible just to the north of the golf resort. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high- resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. Image courtesy NASA GSFC, MITI, ERSDAC, JAROS, and U.S./Japan ASTER Science Team |
|
Smoke from Fires in Greece
| Title |
Smoke from Fires in Greece |
| Description |
Besides laying waste to huge areas of forest, fires [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14474 ] burning in Greece in August 2007 released pollutants that traveled across the Mediterranean Sea and into Africa. This image shows aerosols—tiny solid or liquid particles suspended in air—observed by the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite layered on the photo-like Blue Marble [ http://earthobservatory.nasa.gov/Newsroom/BlueMarble/ ] composite image. Relatively clear air is transparent. Highest aerosol concentrations are pink. On August 26, 2007, aerosols from the fires on the southwestern coast of Greece took a fairly direct route across the Mediterranean Sea to the western part of the Libyan coast. A large pool of smoke collected over the Gulf of Sirte, off the Libyan coast. Another pocket of thick aerosols appears over Algeria. These particles are probably smoke emitted from fires burning in Algeria [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14478 ] over a long stretch of the coastal Atlas Mountains. Farther south over the deserts of northern Africa, the light green areas of moderate aerosol amounts could be smoke or dust. On August 27, 2007, aerosols still crossed the Mediterranean Sea, but they took a more circular route. They spread southward in a clockwise direction from Greece, across the island of Crete, and concentrated thickly over eastern Libya. The other large pocket of aerosols—the pink patch hovering over the border of Libya and Algeria—may include smoke from Algeria and Greece. As on the previous day, some aerosols collected over Egypt and eastern Libya. OMI detects the amount of light of different wavelengths that the atmosphere scatters back to space, the amount of backscattered sunlight is affected by what is in the atmosphere. To make an aerosol index with OMI data, scientists compare the amount of ultraviolet (UV) light the atmosphere scatters back at given place and time to the amount of UV light that the atmosphere would scatter back if it were totally clear. You can download a KMZ file KMZ file of the smoke from Greece suitable for use with Google Earth [ http://earth.google.com/ ] for both August 26 [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2007/greece_omi_2007238.kmz ] and August 27. [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2007/greece_omi_2007239.kmz ] Image courtesy Omar Torres, OMI Science Team, and Colin Seftor, NASA NPP Science Team. |
|
Storms in the Eastern Medite
…
| Title |
Storms in the Eastern Mediterranean |
| Description |
Heavy snow caused chaos in the usually temperate Eastern Mediterranean starting on January 22, 2004 and continuing through January 25. Powerful storms swept through Greece, Jordan, Egypt, Lebanon, Romania, Bulgaria, Italy and Turkey. Snow fell in Turkey, Bulgaria, Greece, and parts of Italy, including Rome. The hardest hit by the storm was Turkey, where the weather has been blamed for 12 deaths, including those of two boys who froze to death traveling between home and school. The storm closed roads and knocked out power throughout much of the Eastern Mediterranean. As the clouds moved out of the area on January 27, 2004, the Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) on the Aqua satellite caught this unusual image of Western Turkey covered in snow. Local media reports say that Istanbul received the equivalent of a month?s precipitation in 24 hours. The high-resolution image provided above has a resolution of 500 meters per pixel. The image is available in additional resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2004027-0127/Turkey.A2004027.1125 ], including MODIS? maximum resolution of 250 meters per pixel. Image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Texas-sized Dust Storm Sweep
…
| Title |
Texas-sized Dust Storm Sweeps over Egypt |
| Description |
A thick and massive cloud of Saharan Desert dust filled the skies over most of Egypt and eastern Libya on January 22, 2004. Roughly the size of the U.S. state of Texas, the tan-colored blanket of dust almost completely obscures the view of the surface in this true-color image of the area, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA?s Aqua satellite. Blowing northeastward over the southeastern Mediterranean, toward Israel and Lebanon, the dust is so thick in some places it gives the appearance of a solid land mass extending out into the water when seen from above. The bright white patches in this scene are clouds, which are higher in elevation than the dust. The high-resolution image available above is 500 meters per pixel. This scene is also available at MODIS? fullest resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov/ ] NASA GSFC |
|
Texas-sized Dust Storm Sweep
…
| Title |
Texas-sized Dust Storm Sweeps over Egypt |
| Description |
The massive Saharan dust storm, originating on Jan. 22, continued spreading north and eastward across Egypt on Jan. 23, 2004. In this true-color scene, the dust (tan pixels) can be seen blowing over the Sinai Peninsula and blanketing parts of Israel, Syria, western Iraq, and almost all of Jordan. To the south, the Red Sea is almost completely obscured as the dust also crosses over into Saudi Arabia. The bright white patches are clouds. This image was acquired by the Moderate Resolution Imaging Spectroradiomater (MODIS), flying aboard NASA's Terra satellite. Notice the vertical discontinuity running vertically down through the image just right of center. This shows where two images from consecutive satellite overpasses were stitched together to make one image. The high-resolution version available above is 500 meters per pixel, but the scene is also available at MODIS' fullest resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov/ ] NASA GSFC |
|
The Great Sand Sea
| Title |
The Great Sand Sea |
| Description |
A dust storm is spilling sand out over the Mediterranean Sea off the coast of Libya (left) and Egypt (right) on May 28, 2003. This region of desert at the bottom of the image is called the "Great Sand Sea. " The darker-colored area to the east of the countries' border is the Qattara Depression. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS' maximum spatial resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Floods Across Africa's Sahel
| Title |
Floods Across Africa's Sahel |
| Description |
Unusually heavy rains fell during West Africa's rainy season in 2006, bringing devastating floods to many countries. Nearly 26,000 were left homeless in Niger and Burkina Faso, the most severely affected countries, reported the United Nations News Service. [ http://www.reliefweb.int/rw/RWB.NSF/db900SID/KHII-6TJ4NS?OpenDocument&rc=1&emid=FL-2006-000133-NE ] The floods extended south of Niger into Nigeria. On September 18, 2006, the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image of flooding along the Sokoto River and its tributaries. The river, only faintly visible in early September (lower image), formed a wide blue ribbon across northern Nigeria on September 18. Though the unusually heavy rains may have made the Sokoto River flood larger than average, the flood seen here is likely the river's annual, seasonal flood. Like the Nile River in Egypt (before it was controlled by dams), the Sokoto floods annually during the rainy season, spreading fresh sediment over its flood plain. The river is an important source of water in the generally arid region, and it provides the means for growing irrigated crops. Indeed, strips of bright green vegetation line the river in these images. The rains have also brought a brush of green to the tan, sparsely vegetated areas away from the river. In these false-color images, clouds are pale blue and white. The large images provide a wider view of the region, including much of Niger to the north. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?NAfrica_2_04/2006261 ] of Nigeria are available from the MODIS Rapid Response Team. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
Floods Across Africa's Sahel
| Title |
Floods Across Africa's Sahel |
| Description |
Unusually heavy rains fell during West Africa's rainy season in 2006, bringing devastating floods to many countries. Nearly 26,000 were left homeless in Niger and Burkina Faso, the most severely affected countries, reported the United Nations News Service. [ http://www.reliefweb.int/rw/RWB.NSF/db900SID/KHII-6TJ4NS?OpenDocument&rc=1&emid=FL-2006-000133-NE ] The floods extended south of Niger into Nigeria. On September 18, 2006, the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image of flooding along the Sokoto River and its tributaries. The river, only faintly visible in early September (lower image), formed a wide blue ribbon across northern Nigeria on September 18. Though the unusually heavy rains may have made the Sokoto River flood larger than average, the flood seen here is likely the river's annual, seasonal flood. Like the Nile River in Egypt (before it was controlled by dams), the Sokoto floods annually during the rainy season, spreading fresh sediment over its flood plain. The river is an important source of water in the generally arid region, and it provides the means for growing irrigated crops. Indeed, strips of bright green vegetation line the river in these images. The rains have also brought a brush of green to the tan, sparsely vegetated areas away from the river. In these false-color images, clouds are pale blue and white. The large images provide a wider view of the region, including much of Niger to the north. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?NAfrica_2_04/2006261 ] of Nigeria are available from the MODIS Rapid Response Team. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
NGC 4755: A Jewel Box of Sta
…
| Title |
NGC 4755: A Jewel Box of Stars |
| Explanation |
The great variety of star colors in this open cluster [ http://www.seds.org/messier/open.html ] underlies its name: The Jewel Box [ http://www.seds.org/messier/xtra/ngc/n4755.html ]. One of the bright central stars is a red supergiant, in contrast to the many blue stars that surround it. The cluster [ http://adsabs.harvard.edu/cgi-bin/nph- bib_query?bibcode=1963MNRAS.126...11F ], also known as Kappa Crucis [ http://adsabs.harvard.edu/cgi-bin/nph- bib_query?bibcode=1984A%26AS...56..373D ] contains just over 100 stars, and is about 10 million years old. Open clusters [ http://antwrp.gsfc.nasa.gov/apod/open_clusters.html ] are younger, contain few stars, and contain a much higher fraction of blue stars than do globular clusters [ http://antwrp.gsfc.nasa.gov/apod/globular_clusters.html ]. This Jewel Box [ http://www.iucaa.ernet.in/~vam/akksem/clusters/ngc4755.html ] lies about 7500 light-years [ http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980211a.html ] away, so the light that we see today was emitted from the cluster before even the Great Pyramids [ http://www.pbs.org/wgbh/nova/pyramid/ ] in Egypt [ http://www.cia.gov/cia/publications/factbook/geos/eg.html ] were built. The Jewel Box, pictured above [ http://www.mso.anu.edu.au/~bessell/thumbnails/ ], spans about 20 light-years, and can be seen with binoculars towards the southern constellation [ http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.ht ml ] of Crux [ http://www.astronomical.org/constellations/cru.html ]. |
|
SN 1006: History's Brightest
…
| Title |
SN 1006: History's Brightest Supernova |
| Explanation |
Suddenly, in the year 1006 AD, a new star [ http://www.noao.edu/outreach/press/pr03/pr0304.html ] appeared in the sky. Over the course of just a few days, the rogue star became brighter than the planet Venus [ http://www.nineplanets.org/venus.html ]. The star, likely the talk of everyone who could see it, was recorded by people who lived in areas now known as China [ http://www.cia.gov/cia/publications/factbook/geos/ch.html ], Egypt [ http://www.cia.gov/cia/publications/factbook/geos/eg.html ], Iraq [ http://www.cia.gov/cia/publications/factbook/geos/iz.html ], Italy [ http://www.cia.gov/cia/publications/factbook/geos/it.html ], Japan [ http://www.cia.gov/cia/publications/factbook/geos/ja.html ], and Switzerland [ http://www.cia.gov/cia/publications/factbook/geos/sz.html ]. The celestial newcomer, now known to be a supernova [ http://heasarc.gsfc.nasa.gov/docs/snr.html ], took months to fade. Modern observations have been used to measure the speed of the still-expanding shock wave [ http://antwrp.gsfc.nasa.gov/apod/ap030118.html ], allowing a better estimate of its distance [ http://www.astro.ucla.edu/~wright/distance.htm ] and hence a better estimate of the true brightness of the supernova [ http://antwrp.gsfc.nasa.gov/apod/ap020714.html ]. It turns out SN 1006 [ http://www.seds.org/~spider/spider/Misc/sn1006.html ] likely achieved an apparent visual magnitude [ http://www.phys.ksu.edu/~wysin/astro/magnitudes.html ] of -7.5, making it the brightest supernova [ http://wave.xray.mpe.mpg.de/rosat/calendar/1997/jul ] on record. The shock wave was imaged in 1998 from CTIO [ http://www.ctio.noao.edu/ ] (left panel), and then subtracted from a similar image taken in 1986 (right panel), highlighting the relative expansion. |
|
Attacking Mars
| Title |
Attacking Mars |
| Explanation |
The Spirit rover [ http://marsrovers.jpl.nasa.gov/overview/ ] attacked Mars again late last month. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near Columbia Hills [ http://antwrp.gsfc.nasa.gov/apod/ap040628.html ]. Spirits Front Hazard Avoidance Camera captured [ http://marsrovers.jpl.nasa.gov/gallery/all/spirit_f175.html ] the rover's Instrument Deployment Device above as it guided the Microscopic Imager to get a closer look at a rock dubbed [ http://marsrovers.jpl.nasa.gov/mission/status_spiritAll.html#sol175 ] Breadbox. Images taken [ http://marsrovers.jpl.nasa.gov/gallery/all/spirit_m175.html ] by the Microscopic Imager show a rock surface consistent [ http://news.bbc.co.uk/1/hi/sci/tech/3889263.stm ] with basalt [ http://volcanoes.usgs.gov/Products/Pglossary/basalt.html ] corroded by ancient groundwater [ http://www.epa.gov/safewater/ ]. Structures with similar origins can be found, for example, in the Western Desert [ http://www.fao.org/ag/agl/swlwpnr/reports/y_nf/egypt/e_wdsrt.htm ] of Egypt [ http://www.cia.gov/cia/publications/factbook/geos/eg.html ] on Earth. The above picture [ http://photojournal.jpl.nasa.gov/catalog/PIA06359 ] taken on June 30, the 175th Martian day [ http://marsrovers.jpl.nasa.gov/spotlight/spirit/a3_20040108.html ] that the Spirit rover has been on the red planet [ http://www.nineplanets.org/mars.html ]. |
|
Nabta: Older than Stonehenge
| Title |
Nabta: Older than Stonehenge |
| Explanation |
In the Sahara Desert [ http://somerset.qld.edu.au/student/10_CE/MINTZ%20David/d3.htm ] in Egypt [ http://www.sis.gov.eg/ ] lie the oldest known astronomically aligned stones in the world: Nabta [ http://www.Colorado.EDU/PublicRelations/NewsReleases/1998/Oldest_Astronomical_Megalith_A.html ]. Over one thousand years before the creation of Stonehenge [ http://antwrp.gsfc.nasa.gov/apod/ap971217.html ], local herders built a stone circle and other structures on the shoreline of a lake that has long since dried up. Over 6000 years ago, stone slabs three meters high were dragged over a kilometer to create the site. Shown above [ http://www.colorado.edu/PublicRelations/Egypt.html ] is one of the stones that remains. Little is known [ http://www.lead.org/lead/international_sessions/okinawa/papers/schell.htm ] about the ultimate purpose of Nabta [ http://www.smu.edu/~anthrop/fwendorf.html ] and the nature of the people who built it. |
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