This space radar image of Athens, Greece, shows the sprawling, modern development of this ancient capital city. Densely populated urban areas appear in shades of pink and light green. The Acropolis is the dark green triangular patch in the center of the image. Archaeological discoveries indicate Athens has been continuously occupied for at least the last 5,000 years. Numerous ships, shown as bright dots, are seen in the harbor areas in the upper left part of the image. The port city of Piraeus is at the left center. This image is 45 kilometers by 45 kilometers (28 miles by 28 miles) and is centered at 37.9 degrees north latitude, 23.7 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations are as follows: red is L-band, horizontally transmitted and received, green is L-band, horizontally transmitted and vertically received, and blue is C-band, horizontally transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 2, 1994 onboard 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. #####
Fires in Greece
Title
Fires in Greece
Description
Deadly wildfires in southern Greece wafted thick clouds of smoke over the Ionian Sea and southward to the Mediterranean in late August 2007. This image of Greece was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov ] satellite on August 26, and places where MODIS detected actively burning fires are outlined in red. A line of fires stretches along the western coast of Greece's Peloponnesus Peninsula. To the northeast, a large fire is casting a plume of smoke over Athens. According to news reports [ http://news.bbc.co.uk/2/hi/europe/6965337.stm ] from the British Broadcasting Corporation (BBC), at least 60 people had been killed by the fires as of August 27. Hundreds of homes had been burned and thousands had to evacuate. The government suspects that the fires were caused by arson, and it has declared a national emergency to deal with the situation. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides twice-daily [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_3_03 ] images of the region in additional resolutions and formats, including an infrared-enhanced version that highlights burn scars. NASA image courtesy the MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center
Smoke from Fires in Greece
Title
Smoke from Fires in Greece
Description
Deadly wildfires in southern Greece wafted thick clouds of smoke over the Mediterranean Sea in late August 2007. According to news reports [ http://news.bbc.co.uk/2/hi/europe/6965337.stm ] from the British Broadcasting Corporation (BBC), at least 60 people had been killed by the fires as of August 27. Hundreds of homes had been burned, and thousands of people had to evacuate, many by helicopter. The government suspects that the fires were caused by arson, and it has declared a national emergency to deal with the situation. Firefighters from more than 20 countries came to help control the fires. This image of Greece was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov/ ] satellite on August 26, and places where MODIS detected actively burning fires are outlined in red. A line of fires stretches along the western coast of Greece's Peloponnesus Peninsula. To the northeast, a large fire is casting a plume of smoke over Athens. With its brownish tinge, the smoke pooled over the Gulf of Sirte could easily be mistaken for dust from the deserts of Libya. Dust storms often travel the other direction across the Mediterranean: from Africa to Greece. [ http://visibleearth.nasa.gov/view_rec.php?id=16593 ] The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides twice-daily [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_3_03 ] images of the region in additional resolutions and formats. More recent images of the area (August 28) [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?Europe_3_03/2007240 ] show that the fires were still burning, but winds appeared to be calmer. Calmer winds and partly cloudy skies may have provided a brief break for firefighters. You can download a 250-meter-resolution KMZ file of the smoke from Greece [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2007/greece_tmo_2007238.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image created by Jesse Allen, using data obtained from the Goddard Land Processes data archives (LAADS). [ http://laads.gsfc.nasa.gov/ ]
The Analemma and the Temple
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Title
The Analemma and the Temple of Olympian Zeus
Explanation
An analemma [ http://www.analemma.com/ ] is that figure-8 curve you get when you mark the position [ http://www.twigsdigs.com/sundials/office/ ] of the Sun at the same time each day throughout planet [ http://antwrp.gsfc.nasa.gov/apod/ap030626.html ] Earth's year. Above, 47 separate exposures [ http://www.perseus.gr/Astro-Solar-Analemma-100000.htm ] (plus one foreground exposure) were recorded on a single piece of film to illustrate this annual cycle of solar motion from March 30, 2003 to March 30, 2004. In the remarkable foreground are standing Corinthian columns of the ancient Temple of Olympian Zeus [ http://en.wikipedia.org/wiki/ Temple_of_Olympian_Zeus_%28Athens%29 ] in Athens, Greece. Solstices [ http://www.archaeoastronomy.com/ index.shtml ], like the one that occurred [ http://aa.usno.navy.mil/data/docs/ EarthSeasons.html ] at 0022 UT on December 22, correspond to the bottom of the figure-8 or the southernmost excursion of the Sun in the sky. The tilt of planet Earth's axis and the variation in speed as it moves around its orbit combine to produce the graceful analemma curve [ http://www.analemma.de/english/analem.html ].
Abell 2597's Cosmic Cavities
Title
Abell 2597's Cosmic Cavities
Explanation
Typical of [ http://chandra.harvard.edu/xray_sources/ galaxy_clusters.html ] large galaxy clusters billions of [ http://www.anzwers.org/free/universe/2billion.html ] light-years away, Abell 2597 features hundreds of galaxies embedded in [ http://antwrp.gsfc.nasa.gov/apod/ap011024.html ] a cloud of multimillion degree gas which glows in x-rays. This Chandra Observatory [ http://chandra.harvard.edu/about/ top_ten.html ] x-ray image shows [ http://chandra.harvard.edu/photo/2002/1269/index.html ] the hot gas in this cluster's central regions and also reveals two large dark cavities within the x-ray glow, one below and right of center, the other above and left. Not a comment on dental health, Abell 2597's cavities [ http://chandra.harvard.edu/press/02_releases/ press_010802.html ] are about 60,000 light-years across. They are thought to be remnants of a 100 million year old explosion originating from a supermassive black hole at the cluster's core. But the dim ghost cavities [ http://xxx.lanl.gov/abs/astro-ph/0110554 ] are not completely empty or they would have collapsed long ago. Instead they are likely filled with hotter gas, high energy particles, and magnetic fields and are moving away from the cluster center, like bubbles rising in champagne. Over the life of a galaxy cluster [ http://antwrp.gsfc.nasa.gov/apod/ap001031.html ] such explosions may happen over and over, creating a series of cavities which transport magnetic fields [ http://www.ohiou.edu/news/01-02/183.html ] away from the cluster center. In fact, radio observations [ http://antwrp.gsfc.nasa.gov/apod/ap011101.html ] suggest another explosion has since occurred in the center of Abell 2597.
ISS and Discovery Transit th
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Title
ISS and Discovery Transit the Sun
Explanation
That large sunspot [ http://antwrp.gsfc.nasa.gov/apod/ap031025.html ] near the right edge of the Sun is actually not a sunspot at all. It's the International Space Station (ISS [ http://www.nasa.gov/mission_pages/station/structure/ index.html ]) and the Space Shuttle Discovery [ http://antwrp.gsfc.nasa.gov/apod/ap020126.html ] on mission STS-114 [ http://www.nasa.gov/returntoflight/main/index.html ]. In the past, many skygazers [ http://spaceflight.nasa.gov/realdata/sightings/ ] have spotted the space station and space shuttles as bright stars gliding [ http://antwrp.gsfc.nasa.gov/apod/ap001214.html ] through twilight skies [ http://antwrp.gsfc.nasa.gov/apod/ap020426.html ], still glinting [ http://antwrp.gsfc.nasa.gov/apod/ap010807.html ] in the sunlight while orbiting 200 kilometers or so above the Earth's surface. But here, astronomer Anthony Ayiomamitis took advantage of a rarer opportunity to record the spacefaring combination [ http://www.perseus.gr/Astro-Sat-Trans-2005-07-28.htm ] moving quickly in silhouette across the solar disk. He snapped the picture on Thursday, July 28th from Athens, Greece. Launched [ http://antwrp.gsfc.nasa.gov/apod/ap050727.html ] on Tuesday, Discovery joined with [ http://www.aaw-darmstadt.de/sts-114.htm ] the ISS [ http://www.syrma.net/trabajos/fotos/20050518/transitoISS/ index.html ] Thursday, making the already large space station seem to loom even larger [ http://www.astromeeting.de/satellites/050714ISSb1024.htm ].
Space Radar Image of Athens,
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PIA01824
Sol (our sun)
Title
Space Radar Image of Athens, Greece
General Description
International Space Station Imagery
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