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View from Titan’s Surface November 30, 2005

Posted by jtintle in European Space Agency, Huygens, JPL, NASA, Saturn, Space Fotos, Titan, University of Arizona.
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View from Titan's Surface

Target Name: Titan
Is a satellite of: Saturn
Mission: Cassini-Huygens
Spacecraft: Huygens Probe
Instrument: Descent Imager/Spectral Radiometer
Product Size: 504 samples x 718 lines
Produced By: University of Arizona
Full-Res TIFF: PIA06440.tif (362.5 kB)
Full-Res JPEG: PIA06440.jpg (21 kB)

Original Caption Released with Image: Images from the European Space Agency’s Huygens probe descent imager/spectral radiometer side-looking imager and from the medium resolution imager, acquired after landing, were merged to produce this image.

The horizon’s position implies a pitch of the imager/spectral radiometer, nose-upward, by 1 to 2 degrees with no measurable roll. “Stones” in the foreground are 4 to 6 inches (10 to 15 centimeters) in size, presumably made of water ice, and these lie on a darker, finer-grained substrate. A region with a relatively low number of rocks lies between clusters of rocks in the foreground and the background and matches the general orientation of channel-like features in the panorama of PIA06439). The scene evokes the possibility of a dry lakebed.

The Huygens probe was delivered to Saturn’s moon Titan by the Cassini spacecraft, which is managed by NASA’s Jet Propulsion Laboratory, Pasadena, Calif. NASA supplied two instruments on the probe, the descent imager/spectral radiometer and the gas chromatograph mass spectrometer.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov.
Image Credit: ESA/NASA/JPL/University of Arizona

Radar reveals ice deep below Martian surface November 30, 2005

Posted by jtintle in JPL, Mars, MARSIS antenna, NASA, NewScientist, Space Fotos.
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NewScientist.com news service
Maggie McKee

The first ever underground investigation of another planet has been performed by a radar antenna aboard Europe’s Mars Express spacecraft. The instrument probed two kilometres below the Martian surface and found tantalising hints of liquid water pooling in a buried impact crater.

The MARSIS antenna was deployed successfully in June 2005 after a series of glitches. It works by sending radio pulses towards the Red Planet and then analysing the time delay and strength of the pulses that bounce back. The radio waves that penetrate the surface rebound when they encounter a sub-surface boundary between materials with different electrical properties – such as rock and water.

But aside from one Apollo 17 radar experiment on the Moon in 1972 – which yielded mixed results – the technique had never been tested.

The most exciting part of this experiment is simply “that it works”, says MARSIS co-leader Jeff Plaut of NASA’s Jet Propulsion Laboratory in Pasadena, California, US.

William T K Johnson, MARSIS manager at NASA’s Jet Propulsion Laboratory in Pasadena, California, US, agrees. “This is very experimental,” he says. “We wondered – can we see anything in the subsurface? The answer to that is yes.”

Ice bowl

Johnson and colleagues have now revealed subsurface measurements of two regions in the planet’s northern hemisphere – the mid-latitude lowlands called Chryse Planitia and the northern polar cap.

They believe a 250-kilometre-wide circular structure that lies between 1.5 and 2.5 kilometres below the surface of Chryse Planitia is an impact crater that was buried with volcanic ash or soil several billion years ago. The team sees no radar boundaries in material that fills the bowl of the crater and the radar signals lose little strength when passing through it. That suggests the infill must contain a large proportion of ice, which is nearly transparent to radar.

Substantial amounts of ice in the soil would make sense given the crater’s location in what appears to be a basin where ancient rivers once converged. “If the water could be captured in a basin and preserved for several billion years, it may still be there,” says Plaut.

Intriguingly, the signal reflected from the bottom of the crater is so strong and appears so flat that it may be liquid water. “If you put water there, that’s what the signal might look like,” Johnson told New Scientist. But he cautions the data is based on only one pass over the region and could be caused by another material.

Rare pass

MARSIS also studied the northern polar cap and found nearly pure water ice stretching down 1.8 kilometres below the surface, with an icy layer of sand underneath.

The researchers are encouraged that such interesting features have emerged from only three data-gathering passes. MARSIS has only been able to make this small number of observations because the subsurface results can only be obtained under special circumstances.

It can best study the subsurface when it is closest to Mars – just 26 minutes of each 7-hour orbit – and when it is also on the planet’s “night” side. That is because energetic electrons in the sunlit portions of the planet’s outer atmosphere, or ionosphere, block the radar’s longest, ground-penetrating wavelengths.

For the last several months, these conditions have not existed at all. But, the conditions are now right again and will remain so until May 2006. The next study regions are in the southern hemisphere, including the south pole.

But gathering the data is only the first step – it then has to be interpreted, which can take scientists months. That is because radar signals travel at different speeds through the ionosphere depending on their wavelength, and the ionosphere itself varies in size depending on the Sun’s activity.

“The ionosphere is always around pestering us,” says Johnson. He adds that so far the ionosphere has prevented the instrument’s longest wavelengths – which could reach down as far as five kilometres – from returning data.

Journal reference: Science (DOI: 10.1126/science.1122165)

Source: New Scientist Space

Record Breaking Paper Airplane November 30, 2005

Posted by jtintle in Earth, Langley Research Center, NASA, Space Fotos.
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Record-breaking paper airplane

This 1992 photograph shows a world record breaking paper airplane inside a hangar at NASA’s Langley Research Center in Virginia.

Image Credit: NASA

Ireland November 30, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Ireland

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (238.2 KB)
500m (912.9 KB)
250m (2.4 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

Explanation: The rich and vibrant greens in this image depict the aptly-named “Emerald Isle?. Ireland (also called the ‘Republic of Ireland’) comprises about 5/6 of the island, while Northern Ireland, a region of the United Kingdom, encompasses the remaining portion. The darker colors in this image signify the coastal mountain ranges, while the lighter colors indicate the central lowlands or plains. In the past, forests covered the entire island, but the island was virtually stripped of its trees in the 17th century. Since then, agriculture has dominated the landscape, although currently Ireland’s economy is dominated by the industrial and service sectors. Ireland is located at high latitude (between 51.5 and 55.5 degrees North), but its climate is very mild: the average temperature in Winter is about 4 degrees Celsius (39 degrees Fahrenheit), while the average Summer temperature is about 16 degrees Celsius (61 degrees Fahrenheit). This condition is caused by the North Atlantic Current or Drift (of which the Gulf Stream is a part); warm water from the Gulf of Mexico is carried to the North Atlantic by strong ocean currents. Some of the water evaporates, making the water that remains much saltier and colder, and, therefore, more dense. It then sinks towards the ocean floor and is carried back in the direction from which it came. Recent research by NASA and other scientists indicates that this conveyor belt-like system may have been, and continue to be, disrupted by global warming.

Crater Interior November 30, 2005

Posted by jtintle in JPL, Mars, Mars Global Surveyor, NASA, Space Fotos.
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Medium-sized view of MGS MOC Picture of the Day, updated daily
Credit: NASA/JPL/Malin Space Science Systems

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows complexly-eroded terrain within a partially-filled impact crater in Noachis Terra.
Location near: 48.5°S, 336.2°W
Image width: ~3 km (~1.9 mi)
Illumination from: upper left
Season: Southern Summer

Polar Lines November 30, 2005

Posted by jtintle in ASU, JPL, Mars Odyssey, NASA, Space Fotos, Thermal Emission Imaging System (THEMIS).
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Medium-size image for 20051130a

Image Credit: NASA/JPL/ASU
Vital Statistics
Location: 79.7S,249.1E Released: 2005-11-30 Instrument: VIS
Image Size: 16.7×51.1 km, 972×2989 px Resolution: 17m

This linear features near the South Polar Cap appeared during the height of southern summer.

Reflections on the Horsehead Nebula November 30, 2005

Posted by jtintle in Antilhue Observatory, APoD, Deep Space, Horsehead nebula, NASA, NGC 2023, Space Fotos.
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See Explanation.  Clicking on the picture will download  the highest resolution version available.
Credit & Copyright: Daniel Verschatse (Antilhue Observatory)

Explanation: Sculpted by stellar winds and radiation, a magnificent interstellar dust cloud by chance has assumed this recognizable shape. Fittingly named the Horsehead Nebula, it is some 1,500 light-years distant, embedded in the vast Orion cloud complex. About five light-years “tall”, the dark cloud is cataloged as Barnard 33 and is visible only because its obscuring dust is silhouetted against the glowing red emission nebula IC 434. Contrasting blue reflection nebula NGC 2023 is visible on the lower left. In this gorgeous color image, both Horsehead and NGC 2023 seem to be caught in beams of light shining from above — but the beams are actually just internal reflections from bright star Sigma Orionis, just off the upper edge of the view.

Mesas with Moats November 29, 2005

Posted by jtintle in JPL, NASA, Space Fotos, TPOD.
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Credit: NASA/JPL/Space Science InstituteMost solid bodies in the solar system are pock marked with circular features that are heedlessly assumed to be “impact craters.? A more careful examination indicates that many of them are likely the result of electrical discharge activity.

In the Electric Universe most craters on celestial bodies are scars left by electrical discharges. Two or more filaments in a Birkeland current remove material from a surface as they rotate around the current’s axis. This action leaves a circular depression with steep walls. As the current varies, the depth of excavation will vary, ften producing terraces along the walls.

Windblown Ripple ‘Scylla’ November 29, 2005

Posted by jtintle in JPL, Mars, Mars Rovers, NASA, Space Fotos.
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Windblown Ripple 'Scylla'

Target Name: Mars
Is a satellite of: Sol (our sun)
Mission: Mars Exploration Rover (MER)
Spacecraft: Opportunity
Instrument: Navigation Camera
Panoramic Camera
Product Size: 1024 samples x 1024 lines
Produced By: Cornell University
Full-Res TIFF: PIA03576.tif (3.15 MB)
Full-Res JPEG: PIA03576.jpg (163.9 kB)

Original Caption Released with Image:
These images were acquired by NASA’s Mars Exploration Rover Opportunity using its panoramic camera on sol 644 (Nov. 15, 2005; upper two images) and its navigation camera on sol 645 (Nov. 16, 2005; lower image). The view looks towards the east, covering a large wind-blown ripple called “Scylla” other nearby ripples and patches of brighter rock strewn with dark cobbles. Panoramic camera bands L4 (601-nanometer wavelength), L5 (535 nanometers), and L6 (482 nanometers) correspond to red, green, and blue bands in the false-color image shown in the upper left. The blue-tinted colors associated with the scours and ripple crests are probably due to the presence of basaltic sands mixed with hematite-rich spherules. Color patterns on the larger ripple flanks are caused by different amounts of reddish dust. The larger ripple flanks have an intricate mixture of erosional scours and secondary ripples extending downward from the main ripple crests, suggesting that these ripples have most recently encountered a period of wind erosion and transport of their outer layers. For comparison, the same panoramic camera image is shown here, but in this case rendered as an approximately true-color composite.
Image Credit: NASA/JPL-Caltech/Cornell

The Caspian Sea November 29, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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The Caspian Sea

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (434.6 KB)
500m (1.5 MB)
250m (3.8 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

The Caspian Sea dominates this image at the crossroads of Europe and Asia. The Caspian is just Southwest of the Ural Mountains, the traditional dividing line between the two continents. It is bordered by Russia and Azerbaijan to the West, Kazakhstan to the North, Turkmenistan to the East, and Iran to the South. The Caspian is the largest inland body of water in the world, measuring over 370,000 square kilometers (143,000 square miles). It is fed by the Volga and Ural Rivers, but it has no natural outlet; instead, water is lost primarily through evaporation. It is relatively shallow, measuring only about a 1 kilometer (0.6 miles) deep; in contrast, the deepest lake in the world (Lake Baikal) is 1.6 kilometers (0.9 miles) deep but only about 31,000 square kilometers (12,000 square miles) in area. The Caspian, although sometimes classified as a lake, is comprised of salt, not fresh, water. The Caspian Sea is a major source of sturgeon, a highly valuable type of fish that produces most of the world’s caviar.

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