What more do we know about Mars' atmosphere? It's hundreds of times thinner than Earth's atmosphere and is made of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen, water, and methane. We also know, from observations that it can support dust storms, dust devils, clouds and gusty winds. With an amazing number of six current live probes exploring Mars (two rovers, a lander, and three orbiters), there are many thousands ofimages available. Only a few, however show atmospheric phenomena. Presented here are some of the best images of Martian atmosphere (and beyond) in action.
High, wispy clouds cover a large portion of Mars, seen in this, the first true-colour image of Mars generated with the OSIRIS orange (red), green and blue color filters. The image was acquired by an instrumenton the ESA's Rosetta probe on Feb. 24, 2007 from a distance of about 240,000 km. Image resolution is about 5 km/pixel. (Credits: ESA © 2007 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA)
Mars' northern orange sky and horizon, seen by NASA's Phoenix Mars Lander. The lander's solar panel and Robotic Arm with a sample in the scoop are also visible. The image was taken by the lander's Surface Stereo Imager looking west during Phoenix's Sol 16 (June 10, 2008), or the 16thMartian day after landing. The image was taken just before the sample was delivered to the Optical Microscope. (NASA/JPL-Caltech/University of Arizona/Texas A&M University)
The brownish gray sky at sunset as it would be seen by an observer on Mars - true color mosaic taken by Mars Pathfinder on sol 24 (June 22, 1996) The sky near the sun is a pale blue color. (NASA/JPL)
High ice cloud over Mars' limb. This composite of red and blue Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images acquired on 6 July 2005 shows an isolated water ice cloud extending more than 30 kilometers (more than 18 miles) above the Martian surface. Clouds such as this are common in late spring over the terrain located southwest of the Arsia Mons volcano. (NASA/JPL/Malin Space Science Systems)
Clouds over crater - the dust storm season in the southern hemisphere of Mars was well underway. This image of an unnamed crater southeast of Hellas Basin shows the encroachment of a storm in the region. Image acquired in 2001 by Mars Odyssey orbiter (17 meter/pixel resolution). (NASA/JPL/ASU)
Dust devil from above. This image taken by the Hi-RISE Camera aboard NASA's Mars Reconnaissance Orbiter catches a dust devil blowing across theMartian surface. Dust devils generally form in the afternoon because the sunlight needs sufficient time to warm the surface. When this image was taken, the local time was about 3:08 p.m. The bright material is the dust within the vortex, and a dark shadow cast by the dust devil is visibleto the left. The diameter of this dust devil is about 200 meters, but at the surface it is probably much smaller. Based on the length of the shadow in this image, the dust devil is on the order of 500 meters tall. (NASA/JPL/University of Arizona)
Martian skies seen above a rolling horizon in this image, part of a larger image called the "McMurdo" panorama, taken in the Martian winter of 2006 by NASA's Mars Exploration Rover Spirit. The tracks in the soil are from Spirits wheels as it rolled through the area earlier. (NASA/JPL/Cornell)
Clouds above the rim of "Endurance Crater" in this image from NASA's Mars Exploration Rover Opportunity. These clouds occur in a region of strong vertical shear. The cloud particles (ice in thismartian case) fall out, and get dragged along away from the location where they originally condensed, forming characteristic streamers. Opportunity took this picture with its navigation camera during the rover's 269thmartian day (Oct. 26, 2004). (NASA/JPL)
Early Spring Dust Storms at the North Pole of Mars. Early spring typically brings dust storms to northern polar Mars. As the north polar cap begins to thaw, the temperature difference between the cold frost region and recently thawed surface results in swirling winds. The choppy dust clouds of several dust storms are visible in this mosaic of images taken by the Mars Global Surveyor spacecraft in 2002. The white polar cap is frozen carbon dioxide. (NASA/JPL/Malin Space Science Systems)
An exaggerated color image mosaic of images from NASA's Mars Rover Opportunity. The clouds can be composed of either carbon dioxide ice or water ice, and can move swiftly across the sky. (NASA/JPL/Cornell)
Large dust storms cover much of Mars' surface in this July, 2001 image, acquired by NASA's Mars Global Surveyor Mars Orbiter Camera. By early July, themartian atmosphere was so hazy that opportunities for high resolution imaging of the planet were very limited. (NASA/JPL/Malin Space Science Systems)
The air is certainly thick enough to fill a parachute. On May 25th, 2008, the HiRISE camera onboard the Mars Reconnaissance Orbiter acquired this dramatic oblique image of the arrival of its sister probe from NASA, the Phoenix Lander, descending on its parachute. Phoenix and its parachute can be barely seen in the larger image with 10 km wide crater informally called "Heimdall" in the background. Although it appears that Phoenix is descending into the crater, it is actually about 20 kilometers in front of the crater. Given the position and pointing angle of MRO, Phoenix is at about 13 km above the surface, just a few seconds after the parachute opened. (NASA/JPL/University of Arizona)
On May 19th, 2005, NASA's Mars Exploration Rover Spirit captured this stunning view as the Sun sank below the rim of Gusev crater on Mars. This Panoramic Camera mosaic was taken around 6:07 in the evening of the rover's 489th martian day, or sol. Spirit was commanded to stay awake briefly after sending that sol's data tothe Mars Odyssey orbiter just before sunset. The image is a false color composite, showing the sky similar to what a human would see, but with the colors slightly exaggerated. (NASA/JPL/Texas A&M/Cornell)
Higher in the Martian skies, we see one of its two moons. The HiRISE camera onboard the Mars Reconnaissance Orbiter acquired this dramatic view of the Martian moon, Phobos, on 23 March 2008, from a distance of 6,800 kilometers. The illuminated part of Phobos is about 21 km across. The most prominent feature is the large impact crater Stickney, in the upper left. With a diameter of 9 km, it is the largest feature on Phobos. (NASA/JPL/University of Arizona)
Even higher in the Martian sky, the Earth and Moon hang in space, as seen from Mars. The HiRISE camera onboard the Mars Reconnaissance Orbiter acquired this image at 5:20 a.m. MST on October 3rd, 2007, at a range of 142 million kilometers, while orbiting Mars
