
ALT King Charles shakes hands with astronaut L. Gordon Fullerton after the 5th free flight of Enterprise in October 1977. Fred Haise is in the foreground with his back to the camera. Behind Charles is Dryden Center Director David R. Scott, and on the right in the background is astronaut John Young. Credit: NASA

ALT Sand dunes shaped like blue-black flames lie next to a central hill within an unnamed, 120-kilometer (75-mile) crater in eastern Arabia Terra. False colors depict the nature of the ground surface: Areas in bluish tints have more fine sand at the surface, while redder tints indicate harder sediments and outcrops of rock. Credit: NASA/JPL/Arizona State University

ALT Western Arabia Terra: This false-color image was made by combining photos taken at infrared wavelengths during local daytime and late at night. The camera was THEMIS, the Thermal Emission Imaging System, aboard NASA's Mars Odyssey orbiter. Broadly speaking, the colors indicate surface materials, with redder colors showing where rocks and hardened sediments are commonest. Tints of greens and blues map the places where finer-grain materials like sand, silt, and dust cover the surface. Credit: NASA/JPL/Arizona State University

ALT Rabe Crater lies among hundreds of thousands of other impact craters in the rough-hewn southern highlands of Mars. Spanning 108 kilometers (67 miles), Rabe is halfway between the martian equator and the south pole, and west of the giant impact basin Hellas. Two features help set Rabe Crater (and several more in its vicinity) apart from most other craters on Mars. Rabe has a flat floor with a pit sunk into it, plus a large field of dunes. A pair of visible-wavelength images together with numerous infrared ones created this false-color THEMIS view that captures portions of both the pit and the dune field. The colors portray the overnight surface temperatures: bluer colors indicate cold places, redder tints warm ones. Credit: NASA/JPL/Arizona State University

ALT The highlands of Terra Sirenum. The infrared imaging gives scientists clues about the nature of the surface. THEMIS photographs patches of ground twice per Martian day—once in late afternoon and then again just before night ends—two times when contrasts in surface temperature are strongest. In this false-color mosaic, THEMIS researchers have colored in blues and greens the areas that are cold at night, while nighttime-warm regions appear in reds, oranges, and yellows. The tints distinguish areas covered in dust and sand (cool colors) from exposures of bare rocks and deposits free of fine-grain material (warm colors). Credit: NASA/JPL/Arizona State University

ALT Saturn's largest and second largest moons, Titan and Rhea, appear to be stacked on top of each other in this true-color scene from NASA's Cassini spacecraft. The north polar hood can be seen on Titan appearing as a detached layer at the top of the moon on the top right. This view looks toward the Saturn-facing side of Rhea (949 miles or 1528 kilometers across). North on Rhea is up and rotated 35 degrees to the right. 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 narrow-angle camera on June 16, 2011, at a distance of approximately 1.1 million miles (1.8 million kilometers) from Rhea and 1.5 million miles (2.5 million kilometers) from Titan. Image scale is 7 miles (11 kilometers) per pixel on Rhea and 9 miles (15 kilometers) on Titan. Credit: NASA/JPL-Caltech/Space Science Institute

ALT A blue hue, present in the northern hemisphere of Saturn is seen here by NASA's Cassini spacecraft. The changing blue hue marks winter at Saturn and is likely due to reduction of ultraviolet sunlight and the haze it produces, making the atmosphere clearer and increasing the opportunity for Rayleigh scattering (scattering by molecules and smaller particles) and methane absorption. This view looks toward the unilluminated side of the rings from about 44 degrees below the ring plane. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were taken with the Cassini spacecraft wide-angle camera on July 29, 2013. Credit: NASA/JPL-Caltech/Space Science Institute

















