In November 1964 NASA launched Mariner 4, the fourth of its ambitious series of robotic explorations of our three inner planet neighbors. Mariner 1 was lost during launch; Mariner 2 successfully flew past Venus; Mariner 3 failed to deploy; but on July 14–15, 1965, the 575-lb Mariner 4 became the first spacecraft to fly past Mars and capture close-up images of another planet from space.
Of course the pictures that Mariner 4 captured were in greyscale and not like the beautiful color views we are used to seeing from spacecraft today. But thanks to one creative scientist at NASA (and a box of crayons) our first scenes of Mars from space were in brilliant color.
This animation is comprised of three images acquired by ESA’s Mars Express spacecraft on Sept. 12, 2017 with its High Resolution Stereo Camera (HRSC). It shows parts of the grooved and pitted surface of Phobos, the larger of Mars’ two natural satellites.
On March 9, 2017, NASA’s Curiosity rover took this picture with its turret-mounted MAHLI camera of the calibration target installed near the “shoulder” of its robotic arm. In addition to color chips and a metric line graph, the target also includes a U.S. coin: a 1909 Lincoln penny, adhered heads-up.
Curiosity’s coin isn’t just for good luck though; it’s also a nod to geologists who typically use familiar objects in field photos to help determine scale. (Curiosity is, after all, one of only two working robot geologists on all of Mars!)
This is a color image of Saturn’s moon Tethys I made from raw images acquired by Cassini on Feb. 1, 2017 in visible-light color channels. It shows the moon’s sunlit leading side—the face that aims in the direction that it moves in its orbit around Saturn. (Click image for a larger version.)
While this icy moon is mostly monochromatic—appearing quite grey even in a color image—there are some subtle variations over large parts of its surface. Here you can just make out a slightly darker bluish band that runs across Tethys’ equatorial region. This is the result of surface weathering by high-energy electrons within Tethys’ orbit. The pale pinker regions to the north and south of the band are thought to be a coating of small ice particles that have been expelled from nearby Enceladus.
Also visible along the terminator is part of the 1,200-mile long, 60-mile-wide Ithaca Chasma, an enormous and ancient canyon system that runs almost all the way from Tethys’ north to south poles.
Tethys is 662 miles (1,065 km) in diameter and composed mostly of water ice and rock. It orbits Saturn at a distance of 183,000 miles (295,000 km) and takes 45.3 hours to complete one orbit. Read more about Tethys here.
This newly-released picture of Pluto isn’t quite what our eyes would perceive… but then our eyes aren’t high-tech scientific imaging sensors like the ones aboard New Horizons! An enhanced-color image made from data acquired by the spacecraft’s LORRI and Ralph cameras on July 13, 2015, this view of Pluto shows the many variations in surface compositions across the planet’s visible area. What the compositions are specifically and how they got to be in the places they’re in are questions still being worked on by scientists, so for now we can all just have fun speculating and enjoy the view!