Interspace News

Titan's Changing Seasons

The Cassini spacecraft records Titan's seasonal hemispheric dichotomy, with the moon's northern half appearing slightly lighter than the southern half in this image. See Two Halves of Titan to learn more about this change on Titan. This view looks toward the trailing hemisphere of Titan (5,150 kilometers, or 3,200 miles across). North on Titan is up and rotated 12 degrees to the right. The image was taken with the Cassini spacecraft narrow-angle camera on Feb. 16, 2010 using a spectral filter sensitive to wavelengths of near-infrared light centered at 889 nanometers. The view was obtained at a distance of approximately 1.1 million kilometers (684,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 28 degrees. Image scale is 7 kilometers (4 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. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Phobos Flyby Success

Mars Express encountered Phobos last night, smoothly skimming past at just 67 km, the closest any manmade object has ever approached Mars’ enigmatic moon. The data collected could help unlock the origin of not just Phobos but other ‘second generation’ moons. GET THE FULL STORY IN THE ROBOTIC SPACEFLIGHT SECTION - CLICK READ MORE BELOW Photo Credit: ESA

Historic Deep Space Network Antenna Starts Major Surgery

Like a hard-driving athlete whose joints need help, the giant "Mars antenna" at NASA's Deep Space Network site in Goldstone, Calif. has begun major, delicate surgery. The operation on the historic 70-meter-wide (230-foot) antenna, which has received data and sent commands to deep space missions for over 40 years, will replace a portion of the hydrostatic bearing assembly. This assembly enables the antenna to rotate horizontally. GET THE FULL STORY IN THE ROBOTIC SPACEFLIGHT SECTION - CLICK READ MORE BELOW Credit: JPL

Herschel Finds Possible Life-Enabling Molecules in Space

The Herschel Space Observatory has revealed the chemical fingerprints of potentially life-enabling organic molecules in the Orion nebula, a nearby stellar nursery in our Milky Way galaxy. Herschel is led by the European Space Agency with important participation from NASA. The new data, obtained with the telescope's heterodyne instrument for the far infrared -- one of Herschel's three innovative instruments -- demonstrates the gold mine of information that Herschel will provide on how organic molecules form in space. The Orion nebula is known to be one of the most prolific chemical factories in space, although the full extent of its chemistry and the pathways for molecule formation are not well understood. By sifting through the pattern of spikes in the new data, called a spectrum, astronomers have identified a few common molecules that are precursors to life-enabling molecules, including water, carbon monoxide, formaldehyde, methanol, dimethyl ether, hydrogen cyanide, sulfur oxide and sulfur dioxide. GET THE FULL STORY IN THE ROBOTIC SPACEFLIGHT SECTION - CLICK READ MORE BELOW Source: ESA/NASA

Rhea's Ice Canyons

On March 2, 2010 Cassini swooped down to within about 100 kilometers of Saturn's ice moon Rhea.Rhea [pronounced REE-uh; adjective: Rhean] is the second largest moon of Saturn, but with a diameter of 1,528 kilometers (949 miles) it is less than a third the size of the largest moon, Titan. Rhea is a small, cold, airless body that is very similar to sister moons Dione and Tethys. As with the other two moons, Rhea is tidally locked in phase with its parent -- one side always faces toward Saturn. Rhea's surface temperatures are also similar to Dione and Tethys, being roughly as warm as -174 degrees Celsius (-281 degrees Fahrenheit) in sunlit areas and ranging down to -220 degrees Celsius (-364 degrees Fahrenheit) in shaded areas. Also like them, it has a high reflectivity (or geometric albedo) suggesting a composition largely of water ice, which behaves like rock in Rhea's temperature range. At 527,040 kilometers (327,490 miles), Rhea is farther away from Saturn than these other two moons, so there is much less tidal attraction from parent Saturn to cause internal heating on Rhea. This has an important effect. The other two moons have more areas of smooth plains than Rhea. Such plains are probably areas where liquid water reached the surface and ponded in depressions such as craters, forming flat surfaces before refreezing and thus erasing existing craters. The lesser internal warmth at Rhea could have resulted in fewer erasures, or there could have been more bombardment on Rhea. Whatever the reason, Rhea is more heavily cratered than Dione and Tethes. Rhea is most famos for it's mysterious linear "wispy" lines with lengths of tens to hundreds of kilometers, often cutting through plains and craters. In 2006, Cassini spacecraft images showed that the wispy areas are subsidence fractures that make canyons (some of them several hundred meters high). The walls of those canyons are bright because darker material falls off them, exposing fresh bright water ice. These fracture cliffs show Rhea may have been tectonically active in its past, and again this type of surface feature also occurs on Dione and Tethys. This image shows one of these "ice canyons". Rhea's density of 1.233 times that of liquid water suggests that Rhea is three quarters ice and one quarter rock. MORE PHOTOS CAN BE FOUND IN THE ROBOTIC SPACEFLIGHT SECTION - CLICK READ MORE BELOW Photo Credit: NASA

Cassini Flys Past Rhea

On March 2, 2010 Cassini swooped down to within about 100 kilometers of Saturn's ice moon Rhea.Rhea [pronounced REE-uh; adjective: Rhean] is the second largest moon of Saturn, but with a diameter of 1,528 kilometers (949 miles) it is less than a third the size of the largest moon, Titan. Rhea is a small, cold, airless body that is very similar to sister moons Dione and Tethys. As with the other two moons, Rhea is tidally locked in phase with its parent -- one side always faces toward Saturn. Rhea's surface temperatures are also similar to Dione and Tethys, being roughly as warm as -174 degrees Celsius (-281 degrees Fahrenheit) in sunlit areas and ranging down to -220 degrees Celsius (-364 degrees Fahrenheit) in shaded areas. Also like them, it has a high reflectivity (or geometric albedo) suggesting a composition largely of water ice, which behaves like rock in Rhea's temperature range. At 527,040 kilometers (327,490 miles), Rhea is farther away from Saturn than these other two moons, so there is much less tidal attraction from parent Saturn to cause internal heating on Rhea. This has an important effect. The other two moons have more areas of smooth plains than Rhea. Such plains are probably areas where liquid water reached the surface and ponded in depressions such as craters, forming flat surfaces before refreezing and thus erasing existing craters. The lesser internal warmth at Rhea could have resulted in fewer erasures, or there could have been more bombardment on Rhea. Whatever the reason, Rhea is more heavily cratered than Dione and Tethes. This photo shows the tiny moons battered surface as viewed by the spacecraft as it neared closest approch. Photo Credit: NASA JPL

Cassini Flys Past Rhea

On March 2, 2010 Cassini swooped down to within about 100 kilometers of Saturn's ice moon Rhea.Rhea [pronounced REE-uh; adjective: Rhean] is the second largest moon of Saturn, but with a diameter of 1,528 kilometers (949 miles) it is less than a third the size of the largest moon, Titan. Rhea is a small, cold, airless body that is very similar to sister moons Dione and Tethys. As with the other two moons, Rhea is tidally locked in phase with its parent -- one side always faces toward Saturn. Rhea's surface temperatures are also similar to Dione and Tethys, being roughly as warm as -174 degrees Celsius (-281 degrees Fahrenheit) in sunlit areas and ranging down to -220 degrees Celsius (-364 degrees Fahrenheit) in shaded areas. Also like them, it has a high reflectivity (or geometric albedo) suggesting a composition largely of water ice, which behaves like rock in Rhea's temperature range. At 527,040 kilometers (327,490 miles), Rhea is farther away from Saturn than these other two moons, so there is much less tidal attraction from parent Saturn to cause internal heating on Rhea. This has an important effect. The other two moons have more areas of smooth plains than Rhea. Such plains are probably areas where liquid water reached the surface and ponded in depressions such as craters, forming flat surfaces before refreezing and thus erasing existing craters. The lesser internal warmth at Rhea could have resulted in fewer erasures, or there could have been more bombardment on Rhea. Whatever the reason, Rhea is more heavily cratered than Dione and Tethes. This photo shows the tiny moons battered surface as viewed by the spacecraft as it neared closest approch. Photo Credit: NASA JPL

Cassini Flys Past Helene

Following a day after a targeted flyby of the moon Rhea, the Cassini spacecraft made its closest approach of the mission to Saturn's moon Helene at about 1,800 kilometers (1,131 miles)on March 2. The small moon is referred to as a trojan moon because it is gravitationally tied to the much larger moon Dione. Photo Credit: NASA

Radar Map of Buried Martian Ice Adds to Climate Record

The Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter has detected widespread deposits of glacial ice in the mid-latitudes of Mars. This map of a region known as Deuteronilus Mensae, in the northern hemisphere, shows locations of the detected ice deposits in blue. The yellow lines indicate ground tracks of the radar observations from multiple orbits of the spacecraft. The ice, up to 1 kilometer (0.6 mile) thick, is found adjacent to steep cliffs and hillsides, where rocky debris from slopes covers and protects the ice from sublimation into the atmosphere. The base map of this image is shaded relief topography obtained by the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor. The image is centered at 42.2 degrees north latitude and 24.7 degrees east longitude. It covers an area 1050 kilometers by 775 kilometers (650 miles by 481 miles). The Shallow Radar instrument on the Mars Reconnaissance Orbiter was provided by the Italian Space Agency. Its operations are led by the University of Rome and its data are analyzed by a joint U.S.-Italian science team. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the spacecraft development and integration contractor for the project and built the spacecraft. GET THE FULL STORY IN THE ROBOTIC SPACEFLIGHT SECTION. CLICK READ MORE BELOW Image Credit: NASA/JPL-Caltech/ASI/University of Rome/Southwest Research Institute

Dunes and Inverted Crater in Arabia Terra

This view of an inverted crater in the Arabia Terra region of Mars is among the images taken by NASA's Mars Reconnaissance Orbiter in early 2010 as the spacecraft approached the 100-terabit milestone in total data returned. The orbiter's High Resolution Imaging Science Experiment (HiRISE) camera recorded this image on Jan. 29, 2010, and the spacecraft surpassed 100 terabits about three weeks later. That is more than three times as much data as the combined total from all other NASA missions that have flown farther from Earth than the orbit of Earth's moon. The Mars Reconnaissance Orbiter reached Mars in 2006 and completed its primary science phase in 2008. The inverted crater seen here spans about 250 meters (about 800 feet) in diameter. Sand in the dark dunes around the crater was probably derived from basalt, a black volcanic rock that is common on Mars. Most craters are depressions, but this one sticks up above the surrounding plains. Such "inverted topography" is found on Mars and Earth where erosion has stripped away surrounding topography. In this case, the crater was filled with sediment, and then subsequent erosion stripped away the terrain around the filled crater. This image covers a swath of ground about 600 meters (about 2,000 feet) wide at about 3 degrees north latitude, 5 degrees east longitude. It is one product from HiRISE observation ESP_016459_1830, which was taken during Mars' northern-hemisphere spring. Other image products from this observation are available at http://hirise.lpl.arizona.edu/ESP_016459_1830. The University of Arizona, Tucson, operates the HiRISE camera, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the spacecraft development and integration contractor for the project and built the spacecraft. Image Credit: NASA/JPL-Caltech/University of Arizona

Salt-Seeking Satellite Shaken By Quake, But Not Stirred

NASA's Aquarius instrument, and the Argentinian spacecraft that will carry it into space, the Satelite de Aplicaciones Cientificas (SAC-D), successfully rode out one of the largest earthquakes in recorded history Feb. 27 with no problems. The instrument and spacecraft are at the satellite systems contractor's satellite integration facility in Bariloche, Argentina. The city of Bariloche, located approximately 588 kilometers, or 365 miles, from the epicenter of the magnitude 8.8 earthquake, experienced light shaking, as indicated by the Modified Mercalli Intensity Scale, which evaluates the effects of earthquakes as experienced by people in the region. No damage was reported to the facility or spacecraft. A separate magnitude 6.3 earthquake in Salta, Argentina, later that day that was triggered by the Chile earthquake was too far away (1,900 kilometers or 1,200 miles) to be felt in Bariloche. This photo shows NASA's Aquarius instrument at INVAP's satellite integration facility in Bariloche, Argentina

NASA Radar Aboard Indian Spacecraft Finds Ice Deposits at Moon's North Pole

Mini-SAR map of the Circular Polarization Ratio (CPR) of the north pole of the Moon. Fresh, “normal” craters (red circles) show high values of CPR inside and outside their rims. This is consistent with the distribution of rocks and ejected blocks around fresh impact features, indicating that the high CPR here is surface scattering. The “anomalous” craters (green circles) have high CPR within, but not outside their rims. Their interiors are also in permanent sun shadow. These relations are consistent with the high CPR in this case being caused by water ice, which is only stable in the polar dark cold traps. We estimate over 600 million cubic meters (1 cubic meter = 1 metric ton) of water in these features. GET THE WHOLE STORY IN THE ROBOTIC SPACEFLIGHT SECTION OF THIS SITE. CLICK READ MORE BELOW

Hidden Janus

The small moon Janus is almost hidden between the planet's rings and the larger moon Rhea. The northern part of Janus can be seen peeking above the rings in this image of a "mutual event" in which Janus (179 kilometers, or 111 miles across) moved past Rhea (1,528 kilometers, or 949 miles across). Mutual event observations such as this one, in which one moon passes close to or in front of another, help scientists refine their understanding of the orbits of Saturn's moons. The view was acquired at a distance of approximately 2.7 million kilometers (1.7 million miles) from Janus and about 3.1 million kilometers (1.9 million miles) from Rhea. Rhea is a slightly overexposed in this image. This view looks toward the northern, sunlit side of the rings from just above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 11, 2009. Scale on Janus is about 16 kilometers (10 miles) per pixel. Scale on Rhea is about 19 kilometers (12 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. Credit: NASA/JPL/Space Science Institute

Mountainous Waves In Saturn's Rings

Ring material, pulled to spectacular heights above the ringplane by the gravity of the moon Daphnis, casts long shadows on Saturn's A ring in this Cassini image taken about a month before the planet's August 2009 equinox. The shadows in this image have lengths as long as 500 kilometers (310 miles), meaning the structures casting the shadows reach heights of almost 4 kilometers (2.5 miles) above the ringplane. These heights are much greater than those previously observed for the Daphnis edge waves , and are very likely caused by the distance between Daphnis and the inner edge of its gap getting unusually small at certain times. Photo Credit: NASA

Zooming in on Heat at Baghdad Sulcus

The right-hand image shows a dramatically improved view of heat radiation from a warm fissure near the south pole of Saturn’s icy moon Enceladus. It was obtained by NASA’s Cassini spacecraft during its Nov. 21, 2009, flyby of that moon. The fissure, named Baghdad Sulcus, is one of four so-called “tiger stripe” features that emit jets of water vapor and ice particles. The tiger stripe runs from the upper left to the lower right of the image. The infrared map, obtained by Cassini’s composite infrared spectrometer, is nearly 10 times more detailed than the image on the left, which was the best previous map of heat from the fissures. That image was obtained in March 2008. The new data show that broad swaths of heat previously detected by the composite infrared spectrometer are confined to a narrow, intense region no more than a kilometer (half a mile) wide along the fracture. The thermal image also reveals that the strength of the signal varies considerably along the length of this fissure segment. The composite infrared spectrometer data indicate that the temperature along Baghdad Sulcus reached more than 180 Kelvin (about minus 140 degrees Fahrenheit). The new map shows how the surface glows at 10 to 16 micron wavelengths of radiation along a 40-kilometer (25-mile) length of Baghdad Sulcus. This covers a region about 10 kilometers to 5 kilometers (6 miles to 3 miles) in width, with the smallest features on the thermal map measuring less than 1 kilometer (half a mile) across. The older March 2008 map covered a larger area but showed no details smaller than about 5 to 9 kilometers (3 to 6 miles) across. The approximate area covered by the November 2009 scan is shown on the March 2008 map by a green rectangle. The brightest colors in both maps do not correspond directly to the higher temperatures, but rather to a combination of higher temperatures and larger areas of warm surface material. The intensity of heat radiation increases as the color shades from violet to red to orange to yellow. No internal heat was detected in the darkest violet regions, and uncolored regions were not mapped by Cassini’s composite infrared spectrometer. The background image is derived from visible-light images taken by Cassini’s imaging science subsystem cameras in July 2005: alignment of the infrared data with the visible-light map is approximate. Analysis of the total amount of infrared energy and the relative amounts of radiation measured at different wavelengths shows that the highest temperatures along Baghdad Sulcus are limited to a region no more than tens of meters (yards) across. Most of the heat measured by the infrared spectrometer probably arises from the warm flanks of the active fractures, rather than from the fractures themselves. The fractures themselves may be even warmer than the 180 Kelvin (minus 140 degrees Fahrenheit) detected – perhaps warm enough for liquid water to exist under the surface. Cassini captured the data for this new mosaic during the spacecraft's close flyby of the moon on Nov. 21, 2009, at a distance of approximately 2,000 to 3,000 kilometers (1,200 to 1,800 miles) from Enceladus. The closeness of the flyby and the speed at which the spacecraft swept past the moon meant that Cassini had to use its thrusters to rotate the spacecraft to track Enceladus, rather than using its slower but more accurate reaction wheels. 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 composite infrared Spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md., where the instrument was built. Credit: NASA/JPL/GSFC/SWRI/SSI

Enceladan Tectonics

This mosaic shows extraordinary details of tectonic deformation in the fractured south polar region of Saturn’s moon Enceladus, where jets of water ice spray outward to form Saturn's E ring. The images were captured by NASA’s Cassini spacecraft. This image and others like it from the close flyby of Enceladus on Nov. 21, 2009, are among the best visible light images Cassini will capture of the region around the “tiger stripes,” the fissures that spray icy particles, water vapor and organic compounds, before the moon's south polar region enters winter darkness for the coming years. Cassini scientists will use these new images to study geological activity associated with the tiger stripes and their effects on the surrounding terrain. In this view, three prominent tiger stripe fractures extend from the bottom center of the mosaic upwards toward the center. From left to right, they are Alexandria Sulcus, Cairo Sulcus, and Baghdad Sulcus. Across the middle of the image, near the northern end of the tiger stripes, a conspicuous pattern of parallel 90-degree bends has formed. The bends curve along similar paths, that is, starting in a direction parallel to tiger stripes at one end and turning perpendicular at the other. Changes in the nature of regional tectonic stresses presumably cause the bends and narrow ridges to form perpendicular to tiger stripe direction. Analyzing systematic tectonic patterns like these throughout the south polar region may lead to an understanding of the forces and mechanism that drive Enceladus' activity. This mosaic was created from six images that are also part of a larger mosaic . The images were re-projected into orthographic map projection. This view looks toward south polar terrain of Enceladus (504 kilometers, 313 miles across). This view is centered on terrain at 73 degrees south latitude, 54 degrees west longitude. The images were obtained in visible light with the Cassini spacecraft narrow-angle camera on Nov. 21, 2009. The view was obtained at distances of approximately 3,200 kilometers (2,000 miles) to 7,000 kilometers (4,300 miles). Image scale is about 18 meters (58 feet) 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 in Washington. 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. Credit: NASA/JPL/SSI

Bursting at the Seams

Dramatic plumes, both large and small, spray water ice out from many locations along the famed "tiger stripes" near the south pole of Saturn's moon Enceladus. The tiger stripes are fissures that spray icy particles, water vapor and organic compounds. More than 30 individual jets of different sizes can be seen in this image and more than 20 of them had not been identified before. At least one jet spouting prominently in previous images now appears less powerful. This mosaic was created from two high-resolution images that were captured by the narrow-angle camera when NASA’s Cassini spacecraft flew past Enceladus and through the jets on Nov. 21, 2009. The south pole of the moon lies near the limb in the top left quadrant of the mosaic, near the large jet that is second from left. Lit terrain seen here is on the leading hemisphere of Enceladus (504 kilometers, 313 miles across). Cassini scientists continue to study the question of whether reservoirs of liquid water exist beneath the surface of the moon. The view was obtained at a distance of approximately 14,000 kilometers (9,000 miles) from Enceladus and at a sun-Enceladus-spacecraft, or phase, angle of 145 degrees. Image scale is 81 meters (267 feet) 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 in Washington. 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. GET THE FULL STORY IN THE ROBOTIC SPACEFLIGHT SECTION - CLICK READ MORE BELOW Credit: NASA/JPL/SSI

First images from ESA’s water mission

In less than four months since launch, the first calibrated images are being delivered by ESA’s SMOS mission. These images of 'brightness temperature' translate into clear information on global variations of soil moisture and ocean salinity to advance our understanding of the water cycle. This image showsbrightness temperature over Scandinavia captured by SMOS. Credits: ESA