Planetary Science News - July, 2007
Dust Storms on Mars
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:
Opportunity Rover To Descend Into Crater
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
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.
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.
Phoenix Lander Prepares For August Launch
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
previously measured up to 70 percent water content in
the soil from orbit. Phoenix reaches Mars in May, 2008.
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.