Wednesday, July 8, 2009

Jupiter and its moon Io , Infrared color composite Image by Spacecraft Feb 28 2007


This is a montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft's Jupiter flyby in early 2007. The Jupiter image is an infrared color composite taken by the spacecraft's near-infrared imaging spectrometer, the Linear Etalon Imaging Spectral Array (LEISA) at 1:40 UT on Feb. 28, 2007. The infrared wavelengths used (red: 1.59 µm, green: 1.94 µm, blue: 1.85 µm) highlight variations in the altitude of the Jovian cloud tops, with blue denoting high-altitude clouds and hazes, and red indicating deeper clouds. The prominent bluish-white oval is the Great Red Spot. The observation was made at a solar phase angle of 75 degrees but has been projected onto a crescent to remove distortion caused by Jupiter's rotation during the scan. The Io image, taken at 00:25 UT on March 1st 2007, is an approximately true-color composite taken by the panchromatic Long-Range Reconnaissance Imager (LORRI), with color information provided by the 0.5 µm ("blue") and 0.9 µm ("methane") channels of the Multispectral Visible Imaging Camera (MVIC). The image shows a major eruption in progress on Io's night side, at the northern volcano Tvashtar. Incandescent lava glows red beneath a 330-kilometer high volcanic plume, whose uppermost portions are illuminated by sunlight. The plume appears blue due to scattering of light by small particles in the plume

Friday, July 3, 2009

Hyperion of 250km across only with chaotic pattern of rotation, Late 2005 Spacecraft Cassini

What lies at the bottom of Hyperion's strange craters? Nobody knows. To help find out, the robot Cassini spacecraft now orbiting Saturn swooped past the sponge-textured moon in late 2005 and took an image of unprecedented detail. That image, shown above in false color, shows a remarkable world strewn with strange craters and a generally odd surface. The slight differences in color likely show differences in surface composition. At the bottom of most craters lies some type of unknown dark material. Inspection of the image shows bright features indicating that the dark material might be only tens of meters thick in some places. Hyperion is about 250 kilometers across, rotates chaotically, and has a density so low that it might house a vast system of caverns inside.

Saturn Back-lighted by Sun, Jan 18 2009 Robot Spacecraft Cassini

In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn recently drifted in giant planet's shadow for about 12 hours and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn, slightly scattering sunlight, in this exaggerated color image. Saturn's rings light up so much that new rings were discovered, although they are hard to see in the image. Seen in spectacular detail, however, is Saturn's E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus and the outermost ring visible above. Far in the distance, at the left, just above the bright main rings, is the almost ignorable pale blue dot of Earth.

A Moon of Saturn: Enceladus, Jun 28 2009 Spacecraft Cassini

Do underground oceans vent through the tiger stripes on Saturn's moon Enceladus? Long features dubbed tiger stripes are known to be spewing ice from the moon's icy interior into space, creating a cloud of fine ice particles over the moon's South Pole and creating Saturn's mysterious E-ring. Evidence for this has come from the robot Cassini spacecraft now orbiting Saturn. Pictured above, a high resolution image of Enceladus is shown from a close flyby. The unusual surface features dubbed tiger stripes are visible in false-color blue. Why Enceladus is active remains a mystery, as the neighboring moon Mimas, approximately the same size, appears quite dead. Most recently, an analysis of dust captured by Cassini found evidence for sodium as expected in a deep salty ocean. Conversely however, recent Earth-based observations of ice ejected by Enceladus into Saturn's E-Ring showed no evidence of the expected sodium. Such research is particularly interesting since such an ocean would be a candidate to contain life.

Thursday, July 2, 2009

ISS: Interational Space Station, Taken from Space Shuttle Discovery Mar 25 2009

Backdropped by a blue and white Earth, the International Space Station is seen from Space Shuttle Discovery as the two spacecraft begin their relative separation. Earlier the STS-119 and Expedition 18 crews concluded 9 days, 20 hours and 10 minutes of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 2:53 p.m. (CDT) on March 25, 2009. Photo credit: NASA

Wednesday, July 1, 2009

S-Ring of Saturn, Cassini Spacecraft Apr 17 2009

Saturn's northern hemisphere is seen here against its nested rings.
This view from the Cassini spacecraft looks toward the unilluminated side of the rings from about 30 degrees above the ringplane. The rings have been brightened relative to the planet to enhance visibility.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera on Feb. 24, 2009 at a distance of approximately 866,000 kilometers (538,000 miles) from Saturn. Image scale is 38 kilometers (24 miles) per pixel.

Rainy Day at Hotei Arcus, Titan a Satellite of Saturn, Cassini Spacecraft May 21 2009

Complex and unique canyon systems appear to have been intricately carved into older terrain by the ample flow of liquid methane rivers on Saturn's moon Titan, as seen in this radar image taken by NASA's Cassini spacecraft on May 21, 2009.
The channels seen here indicate that fluids flowed from high plateaus on the right to lowland areas on the left. In the center of the image, the wide distribution of the channels' tributaries suggests that rainfall is effectively eroding the surface. The bright terrain toward the bottom of the image is interpreted as high cliffs and broken bedrock.
These canyon systems remind us that Titan is (or has recently been) a dynamic world with a complicated geological history. Multiple channels have flowed into a wide, dark arc in the center of this mountainous region. Here, the canyons appear to have been filled by fine-grained materials that appear dark (smooth) to Cassini's synthetic aperture radar. These canyon-filling materials were later carved by a large river channel that winds from the bottom left of the image toward the left center.
The image center is at 71 degrees south latitude, 240 degrees west longitude, and its dimensions are 335 by 289 kilometers (208 by 179 miles). The radar illuminated this area from the top of the image at 18 degrees incidence angle. The areas seen here are typical of other regions observed near Titan's south pole in other flybys

A short but fierce "gullywasher" rainstorm of methane falls on the mountains surrounding the intriguing flows of Titan's Hotei Arcus in this artist's concept by Michael Carroll, based upon radar mapping data from the Cassini spacecraft in orbit around Saturn.
Radar data show that the arc of Hotei is the boundary between rugged mountains to the south and east and a broad valley. Emerging from the mountains are several radar-bright channels that are likely now dry river beds that were carved by flowing methane due to rainfall. Within the valley, the channels end near lobate (blobby) flows some 100 to 200 meters (300 to 600 feet) thick, which some scientists think could be slushy ice lava from cryovolcanoes. These flows are portrayed here as the rough and elevated lighter tan areas in the foreground. It is possible that such phenomena could release methane from beneath the surface, helping to explain how Titan's atmosphere sustains its supply of methane.
The area depicted is located at approximately 28 degrees south latitude and 78 degrees west longitude.

Tethys- Moon of Saturn, Cassini-Huygens, Cassini Orbiter NASA JPL Jun 26 2009




The shadow of the moon Tethys is revealed on Saturn's B and C rings in this image which also includes the planet.
The planet is overexposed in this image in which the exposure time was set to capture the faint shadow on the rings. Tethys itself is not visible in this image. As Saturn approaches its August 2009 equinox, the planet's moons cast shadows onto the rings.
This view looks toward the unilluminated side of the rings from about 20 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on May 12, 2009. The view was obtained at a distance of approximately 1.2 million kilometers (746,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 28 degrees. Image scale is 65 kilometers (40 miles) per pixel.
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 operations center is based at the Space Science Institute in Boulder, Colo.