New HiRISE images detail diverse Mars terrain

New images from the highest-resolution camera ever to orbit Mars show striking new details in diverse terrains that surface the planet. New images from the High Resolution Science Imaging Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter reached Earth on Friday, Sept. 29, and Saturday, Sept. 30.

HiRISE principal investigator Alfred S. McEwen of the University of Arizona Lunar and Planetary Laboratory (LPL) and his team released the first HiRISE image of Mars from mapping orbit, an image of Ius Chasma in the vast Valles Marineris canyon, on Friday afternoon. Team members viewed more new images at LPL's HiRISE Operations Center (HiROC) on the UA campus over the weekend.
Several of these images are available online at http://hiroc.lpl.arizona.edu/images/TRA. The images show never-before-seen structure at such places as:

• polygon-patterned polar terrain in the northern plains. The image shows a location near an area under consideration as a landing site for the Phoenix Scout Mission to Mars in 2008. (LPL scientist Peter Smith is principal investigator for Phoenix.)
• wind-sculpted landforms called 'yardangs' in the Medusae Fossae Formation at the Martian mid-latitudes
• a cliff snaking through the southern edge of Elysium Planitia near Mars' equator
• dramatic pits, buttes and mesas that have eroded from lighter-toned material flanking the very smooth dark plains in Meridiana Planum. (The Mars Exploration Rover 'Opportunity' is about 600 kilometers west of where this image was taken.)
• patterns of parallel dunes and ripples, as well as boulders as small as two meters across, in part of the floor of an ancient Martian outflow channel called Niger Vallis
• a 300-meter-wide, 90-meter-deep trough filled with dunes and peppered with boulders that have fallen from the rocky walls to the floor of the trough, which is in the Cerberus Fossae rift system

The camera returned test images after Mars Reconnaissance Orbiter went into orbit around Mars on March 10, 2006, but those were from altitudes more than eight times higher than orbiter is flying now. Since March, the spacecraft has shrunk its orbit by dipping more than 400 times into the top of the Martian atmosphere to shave velocity. It is now flying in its final, nearly circular orbit at altitudes of 250 to 316 kilometers (155 to 196 miles). The orbit will remain this shape and size for the mission's two-year primary science phase, which begins in November.

During its primary science phase, Mars Reconnaissance Orbiter will return more data about the red planet than all previous missions combined, pouring data to Earth at about 10 times the rate of any earlier Mars spacecraft. Scientists will analyze the information to gain a better understanding of the distribution and history of Mars' water -- whether ice, vapor or liquid -- and of the processes that formed and modified the planet's surface.

For most of October, Mars will be passing nearly behind the sun from Earth's perspective. Communication will be intermittent. Activities will be minimal for Mars Reconnaissance Orbiter and other spacecraft at Mars during this time, and they will resume in early November.

University of Arizona News Release