This mosaic of the Viking 1 Orbiter images f826a33 to 38, taken on September 21, 1978, shows the feature colloquially called “White Rock” which is located on the floor of Pollack Crater in the Sinus Sabaeus region near the Martian equator.
The mosaic was rotated to put north up.
Image Credit: NASA/JPL/Arizona State University/Mosaic by astroarts.org
White Rock got its nickname more than 30 years ago, when scientists first spotted the feature on the floor of Pollack Crater in images taken by the Mariner 9 spacecraft.
Pollack, which is about 90 kilometers wide, has a dark floor, especially over its southern half, where White Rock lies. At the time of Mariner 9, rather contrasty image processing gave White Rock, which measures about 15 by 18 km, a chalky-bright appearance.
This brightness led many scientists to propose White Rock was made of water-deposited sediments, like the salty residue of a dried-up desert lake.
In 2001, however, scientists working with the Thermal Emission Spectrometer (TES) on NASA’s Mars Global Surveyor (MGS) found that White Rock has a dry origin and is built of wind-blown sediments. The bright blocks and ridges have the same brightness as light-colored, dusty regions elsewhere on Mars, and White Rock’s spectra likewise matches these and shows no trace of water.
The wind-sculpted ridges that make up White Rock rise about 300 meters above Pollack Crater’s floor, which shows as dark lanes cutting into the light-colored formation.
While the light material stands up as buttes and ridges, lots of loose material nonetheless surrounds White Rock. At the feature’s northern end lies a field of dunes made of dark, basaltic sand grains. These sand grains probably eroded from the lava that covers the floor of Pollack. The dune shapes suggest that some winds blew from the east or southeast. It is possible these were funneled by the channel, some 500 meters wide, that cuts straight through White Rock.
This is the first color panorama of Utopia Planitia returned by the Viking 2 Lander.
The panorama was created by combining and stitching the .red/.grn/.blu image series 22a003, 22a016 and 22a018.
The images were taken by camera 2 on September 4 and September 6, 1976, in the Martian afternoon looking towards the northeast. The Sun is behind the camera.
The large rock left of the center of the panorama is about 1 meter wide. Because the spacecraft is tilted about 8 degrees to the west, the horizon appears tilted.
Please note that the .red, .grn and .blu images from the Viking Landers don’t have the same maximum wavelength as human vision has and thus a simple RGB combination of these channels could NOT be considered as “true color”.
The panorama presented here was processed further to resemble an approximately true color appearance.
Image Credit: NASA/JPL-Caltech/Panorama by astroarts.org
The following movie shows views of Mars as Mars Express loops between apoapsis (maximum height above the surface), at 10,527 km, to periapsis (lowest height), at just 358 km, and back again.
The giant volcanoes of Mars can be clearly seen at the start of the video, visible as a constellation of dark spots on the desert surface. They are followed by a glimpse of the icy South Pole before plunging into the darkness of the planet’s night side. Daylight returns with a soaring ride over the spiral ices of the Martian North Pole. At the very end, Phobos passes far beneath Mars Express, and the tiny moon’s disk can be seen as a dark circle moving from top to bottom.
The images used to generate this video, 600 in total, were acquired by the Visual Monitoring Camera (VMC) during the 8194th orbit on May 27, 2010, between 02:00 and 09:00 UTC. This is the first such video ever generated from a spacecraft orbiting Mars.
The VMC is a low-resolution, non-scientific digital camera originally used only to confirm the separation of the (later lost) Beagle 2 lander from Mars Express in 2003.
High-resolution view of the Martian surface at Chryse Planitia, produced from nine Viking 1 Lander mid-afternoon images (12a119.bb3, 12a136.bb1, 12a140.bb2, 12a152.bb2, 12a153.bb4, 12a211.bb4, 12a212.bb4, 12a237.bb4 and 12a238.bb2). The images were taken between August 10 and August 20, 1976.
Image Credit: NASA/JPL-Caltech/Mosaic by astroarts.org
This mosaic of 22 Viking 1 Orbiter images (f473s13/17/19/21/23/25/27/29, f474s17/19, and f474s21 to 32), taken on July 11 and July 12, 1980, shows the complex caldera at the summit of Olympus Mons. South is at the top.
The caldera, a composite of as many as seven roughly circular collapse depressions, is 66 by 83 km across. The lowest parts of the floor are over 4 kilometers below the rim of the caldera.
Image Credit: NASA/JPL/Arizona State University/Mosaic by astroarts.org
Note: This is the most complete high-resolution Viking Orbiter image mosaic of the Olympus Mons caldera which has been published to date.
For comparison, here is a mosaic of the Olympus Mons caldera produced by A. Tayfun Oner in 1997 and published on Calvin J. Hamilton’s website “Views of the Solar System”, and here is a mosaic produced by JPL and published in NASA’s Planetary Photojournal.
Mimas with the limb of Saturn as a backdrop.
Image N00151588, taken by Cassini on February 13, 2010, from a distance of approximately 69,730 kilometers.
On February 13, 2010, Cassini flew within 9.500 kilometers of Mimas, the closest encounter yet with Saturn’s Death Star-like moon, which averages 396 kilometers in diameter. Cassini approached from the night side and retreated with a nearly full-phase view of Mimas’ leading hemisphere including the giant Herschel Crater. The highest resolution view of Herschel was obtained from a distance of about 15.000 kilometers. Two multispectral mosaics covered most of the visible disk around the crater. One of the last shots caught by Cassini’s camera shows a full-globe Mimas with the limb of Saturn as a backdrop.
Four of the highest resolution views from Cassini’s flyby (images N00151508/20/25/44, taken from a mean distance of 20,823 kilometers) were assembled to this mosaic and show the giant Herschel Crater and its surroundings. The steep slopes of the 140 kilometers wide crater are about 5 kilometers high, and parts of the floor are approximately 10 kilometers deep. The mosaic was rotated to put north up. (Replaced with an improved version on April 18, 2010.)
Image Credit: NASA/JPL/Space Science Institute/Mosaic by astroarts.org
Cassini was about 71.500 kilometers from Mimas when it captured the images for this false-color composite. Images taken through infrared, blue, and ultraviolet filters produce a view of the moon that emphasizes the interesting bluish-white color splotch on its leading hemisphere, centered on the giant Herschel Crater.
Images taken through infrared, blue, and ultraviolet filters produce these two detailed false-color views of Herschel Crater. The image on the right shows the southern rim of the crater from a distance of about 15.700 kilometers.
This website, AstroArts, is now five years old. Five years is a long time – by internet standards it’s like an eternity. I started conceiving and building the site in late February 2005. Back then the site was located at a free webhosting service with 60 megabytes of storage space. Enough for just a couple of nice picture galleries. But that changed quickly… On May 12, 2006, I registered the domain astroarts.org with a professional webhosting company whom I still use to this day. The site now uses a blogging model based on WordPress and has articles as its centre rather than just static pages with galleries.
Thanks to all of you for visiting this website during the last five years, and I hope you will continue to enjoy this place just as I do!
Next up will be an article with outstanding pictures from Cassini’s flyby of Saturn’s moon Mimas, which ocurred on February 13, 2010. Stay tuned!
Part of the cratered and cracked surface of Saturn’s moon Dione. The images used for this mosaic are clear-filter views taken by Cassini on January 27, 2010, from a distance of about 45.215 km.
Image Credit: NASA/JPL/Space Science Institute/Mosaic by astroarts.org
