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Dark Patch
| Description |
Dark Patch |
| Full Description |
The ancient and battered surface of Saturn's moon Rhea shows a notable dark swath of territory near the eastern limb in this image from Cassini. This view shows principally the Saturn-facing hemisphere on Rhea (1,528 kilometers, or 949 miles across). North is up and tilted 40 degrees to the right. The image was taken with the Cassini spacecraft narrow-angle camera on March 7, 2005, through a filter sensitive to wavelengths of ultraviolet light centered at 338 nanometers. The view was acquired at a distance of approximately 1.8 million kilometers (1.1 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 30 degrees. Resolution in the original image was 10 kilometers (7 miles) per pixel. The image has been contrast-enhanced and magnified by a factor of two to aid visibility. 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. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . For additional images visit the Cassini imaging team homepage http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
April 19, 2005 |
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Haze Over Eastern United Sta
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| Title |
Haze Over Eastern United States |
| Description |
Haze hung over the U.S. East Coast on April 19, 2005, lowering the air quality in many eastern cities, though none reached the EPA's "Code Red" category?unhealthy?. In a few cities, the levels of ozone and particulate matter 2.5 micrometers in diameter or larger entered the range of orange, which indicates the air could be unhealthy for people in sensitive groups, such as the elderly or people with respiratory conditions like asthma. This image of the area was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA?s Terra satellite and stretches from New York southward to North Carolina, encompassing several large Eastern cities, including New York City, Philadelphia, Baltimore, and Washington, D.C. The grayish haze extends outward over the Atlantic Ocean (image right). For more on regional and national air pollution, visit the Environmental Protection Agency?s Air Now [ http://www.epa.gov/airnow/index.html ] Website. To read about how NASA satellite data help air quality forecasters to predict regional air quality, read the feature story A New IDEA in Air Quality Forecasting. [ http://earthobservatory.nasa.gov/Study/IDEA/ ] Image courtesy the MODIS Rapid Response Team, NASA-Goddard Space Flight Center |
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Dust Storm Blows Across Iraq
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Dust Storm Blows Across Iraq |
| Description |
A bright band of dust sweeps down the center of ancient Mesopotamia in this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image, collected on April 19, 2005, by NASA's Aqua [ http://aqua.nasa.gov/ ] satellite. The dust is blowing north out of the Syrian Desert in Iraq and Syria. Though the color matches the ground, the airborne dust is brighter and smoother in texture, making it stand out in the image. The dust blankets the land between the Euphrates River on the east and the Tigris River in the west—the region that nurtured some of the earliest human civilizations. Today, a green band of vegetation makes the Euphrates River easy to see in modern Syria. On the right side of the image, the Tigris is also lined in green as it flows through eastern Iraq. MODIS detected three fires to the east of the Tigris, and they are marked with red dots in this image. 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. |
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Karthala Volcano in Comoros
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| Title |
Karthala Volcano in Comoros Erupts |
| Description |
Villagers on the island of Grand Comore are returning home to ash-tainted water after the Karthala volcano stopped erupting on April 19, 2005. The volcano began spewing ash and gas on April 17, forcing as many as 10,000 people to flee. The Karthala volcano is notoriously active, having erupted more than 20 times since the 19th century. The volcano rises to a height of 2,361 meters on the southern end of Grand Comore, the largest island in the nation of Comoros. Frequent eruptions have shaped the volcano's 3 by 4 kilometer summit caldera, which is shown in these Ikonos images. The top image shows the summit caldera on April 19, 2005, just as the eruption was ending. The bright white cloud on left of center, near the edge of the caldera may be steam from the eruption. The lower image shows the summit caldera on August 4, 2002. Some of the differences between the two images are caused by differences in season and time of day. The top image was taken early in the morning when the eastern sun cast long shadows over the eastern side of the crater. The sun was more directly overhead in the lower image. Beyond differences in lighting, the crater has clearly been changed by the recent eruption. A grey field of ash surrounds the crater and the caldera itself seems larger and deeper. The crater lake that dominates the caldera in the 2002 image is gone entirely. The lake formed after Karthala's last eruption in 1991. In its place are rough, dark grey rocks, possibly cooling lava or rubble from the collapsed crater. Images copyright Space Imaging [ http://www.spaceimaging.com/ ] |
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Karthala Volcano in Comoros
…
| Title |
Karthala Volcano in Comoros Erupts |
| Description |
Villagers on the island of Grand Comore are returning home to ash-tainted water after the Karthala volcano stopped erupting on April 19, 2005. The volcano began spewing ash and gas on April 17, forcing as many as 10,000 people to flee. The Karthala volcano is notoriously active, having erupted more than 20 times since the 19th century. The volcano rises to a height of 2,361 meters on the southern end of Grand Comore, the largest island in the nation of Comoros. Frequent eruptions have shaped the volcano's 3 by 4 kilometer summit caldera, which is shown in these Ikonos images. The top image shows the summit caldera on April 19, 2005, just as the eruption was ending. The bright white cloud on left of center, near the edge of the caldera may be steam from the eruption. The lower image shows the summit caldera on August 4, 2002. Some of the differences between the two images are caused by differences in season and time of day. The top image was taken early in the morning when the eastern sun cast long shadows over the eastern side of the crater. The sun was more directly overhead in the lower image. Beyond differences in lighting, the crater has clearly been changed by the recent eruption. A grey field of ash surrounds the crater and the caldera itself seems larger and deeper. The crater lake that dominates the caldera in the 2002 image is gone entirely. The lake formed after Karthala's last eruption in 1991. In its place are rough, dark grey rocks, possibly cooling lava or rubble from the collapsed crater. Images copyright Space Imaging [ http://www.spaceimaging.com/ ] |
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Karthala Volcano in Comoros
…
| Title |
Karthala Volcano in Comoros Erupts |
| Description |
Villagers on the island of Grand Comore are returning home to ash-tainted water after the Karthala volcano stopped erupting on April 19, 2005. The volcano began spewing ash and gas on April 17, forcing as many as 10,000 people to flee. The Karthala volcano is notoriously active, having erupted more than 20 times since the 19th century. The volcano rises to a height of 2,361 meters on the southern end of Grand Comore, the largest island in the nation of Comoros. Frequent eruptions have shaped the volcano's 3 by 4 kilometer summit caldera, which is shown in these Ikonos images. The top image shows the summit caldera on April 19, 2005, just as the eruption was ending. The bright white cloud on left of center, near the edge of the caldera may be steam from the eruption. The lower image shows the summit caldera on August 4, 2002. Some of the differences between the two images are caused by differences in season and time of day. The top image was taken early in the morning when the eastern sun cast long shadows over the eastern side of the crater. The sun was more directly overhead in the lower image. Beyond differences in lighting, the crater has clearly been changed by the recent eruption. A grey field of ash surrounds the crater and the caldera itself seems larger and deeper. The crater lake that dominates the caldera in the 2002 image is gone entirely. The lake formed after Karthala's last eruption in 1991. In its place are rough, dark grey rocks, possibly cooling lava or rubble from the collapsed crater. Images copyright Space Imaging [ http://www.spaceimaging.com/ ] |
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Fires in Mexico and Central
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| Title |
Fires in Mexico and Central America |
| Description |
Fires continued to burn across southern Mexico, the Yucatan Peninsula, and northern Central America on April 19, 2005. The smoke extends out over the water in both directions: north into the Gulf of Mexico (top), and south over the Pacific Ocean (bottom right). Actively burning fires detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite have been marked in red. An especially intense cluster of fires is burning in northwestern Guatemala, right of image center. The country is suffering from a severe drought that makes normal agricultural burning practices dangerous. In addition, people who are fighting over land in the country set fire to forests as a form of protest or to degrade land in protected forest reserves so that the government will permit salvage logging. This combination of accidental and intentional fire is taking a huge toll on the country's remaining rainforest. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
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