Planetary Science News - July, 2007

A massive dust storm covering about a quarter of Mars's southern hemisphere is "starving" NASA's Mars rovers Spirit and Opportunity, forcing mission managers to put the solar-powered robots on regular nap-time schedules to save energy. Check out these links:

• National Geographic story, July 7, 2007.
  
  
• MSNBC story, June 27, 2007.
  
  
• ASU's THEMIS instrument monitors the dust storms, reported by Astronomy magazine, July 11, 2007.
  
  

NASA's Mars rover Opportunity is scheduled to begin a descent down a rock-paved slope into the Red Planet's massive Victoria Crater this month (July, 2007). This latest trek carries real risk for the long-lived robotic explorer, but NASA and the Mars Rover science team expect it to provide valuable science.

This descent will give scientists a chance to examine and investigate the compositions and textures of exposed materials in the crater's depths for clues about ancient, wet environments. As the rover travels farther down the slope, it will be able to examine increasingly older rocks in the exposed walls of the crater. See the following links for more information:

• Opportunity descends into crater, story by Astronomy magazine, July 2, 2007.
  
  
• Images of dust storms and dust devils on Mars.
  
  

Other Mars Rover Stories

• Rovers get Fourth-Year Brain Boost (Software Update) Your home computer isn't the only one that gets an upgrade for its software! New software was sent by radio to both rovers on Mars and installed, and promise to greatly improve their function. The robots are a year older and a lot smarter!
  
  One update enables the rovers to recognize dust devils and clouds in the martian atmosphere. "The idea is to only save those images that the flight software believes has these features," explains Khaled S. Ali, who supervised the creation of the new software. Another software update confers a skill called "visual target tracking." With visual target tracking, a rover can continuously recognize and navigate toward a target of interest ó say, a boulder. "This allows us to do approaches to targets much more accurately," Ali says.
  
  A new visual-target-tracking feature allows Spirit and Opportunity to "go and touch," much like inquisitive human 4-year-olds. If the software works as designed, the rovers will be able to independently maneuver to targets and probe them with instruments. Previously, it would take as many as 3 martian days for human operators to manually navigate to targets and probe them. Now, the rovers themselves should be able to accomplish this task in a single martian day.
  
  Another feature will help them avoid potential hazards.
  
  
• May, 2007: Mars' Wet Past. A patch of Martian soil analyzed by NASA's rover Spirit is so rich in silica that it may provide some of the strongest evidence yet that ancient Mars was much wetter than it is now. The processes that could have produced such a concentrated deposit of silica require the presence of water.
  
  

NASA's Phoenix lander will launch from Kennedy Space Center in Florida this August. Phoenix is the first in NASA's Scout program of low-cost Mars missions.Ý Its suite of science instruments, designed to perform in-depth chemical, mineralogical, and morphologic analysis on samples of rock and ice dug from a trench, seek to verify the amount of water at the planet's north pole. The Mars Odyssey's Gamma-Ray Spectrometer previously measured up to 70 percent water content in the soil from orbit. Phoenix reaches Mars in May, 2008.

• Planetary Society's story about the launch.
  
  
• Phoenix mission's home page.
  
  

Hexagons on Saturn

Scientists have imaged a large hexagon-shaped feature in the atmosphere of Saturn near its north pole. Surprisingly, the honeycomb-like feature has been seen before. NASA's Voyager 1 and 2 spacecraft imaged it more than two decades ago. Now, having spotted it with the Cassini spacecraft, scientists conclude it is a long-lasting oddity. "This is a very strange feature, lying in a precise geometric fashion with six nearly equally straight sides," said Kevin Baines, atmospheric expert and member of Cassini's Visual and Infrared Mapping Spectrometer (VIMS) instrument team at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We've never seen anything like this on any other planet." The hexagon is nearly 15,000 miles (25,000 kilometers) across, and nearly four Earths could fit inside it. The thermal imagery shows the hexagon extends about 60 miles (100 kilometers) down into the clouds. More information:

• Science Daily's article on Saturn's hexagons.
  
  
• Space.com's article on Saturn's hexagons.