[meteorite-list] Spirit Mars Rover Turns Astronomer

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Sep 7 19:06:47 2005
Message-ID: <200509072305.j87N5gp00646_at_zagami.jpl.nasa.gov>

http://space.com/missionlaunches/050907_spirit_update.html

Night Moves: Spirit Mars Rover Turns Astronomer
By Leonard David
space.com
07 September 2005

>From its "top of the world" vantage point, Spirit has snagged images of
the two Mars moons - Phobos and Deimos. The robot is also assessing
weather features in the dark of the night on Mars. Other nighttime
duties are being discussed, such as charting meteor showers on the red
planet.

"We're actually shunting some power during the daytime. So we'd much
rather use that power to do some science instead of shunting it out as
waste heat," said Jim Bell, an Associate Professor in the Cornell
University Astronomy Department in Ithaca, New York.

Bell is lead scientist for the Panoramic Camera color imaging system
carried by the dual Mars robots: Spirit and Opportunity.

Moons in view

Having so much power has allowed group controllers to task Spirit to
execute nighttime observing campaigns, Bell told SPACE.com.

While each rover is equipped with a Panoramic Camera - or PanCam - the
devices are not telescopes. "Still, we can do some pretty good
astronomy," Bell said.

Spirit has been able to snap shots of both Phobos and Deimos together.
"We're killing two birds with one stone by selecting times when those
two moons pass each other in the sky. That does frequently happen -
every couple of nights," Bell said.

Bell said that, by taking the nighttime photos, a better understanding
of where those two moons are in their respective orbits becomes possible.

"We're getting some good orbital refinement on the positions of the
satellites," Bell added. "They haven't been monitored by astronomers
since the late 1980s."

In addition, by using color filters on Spirit, colors of the two martian
moons can be ascertained, Bell noted.

Weather service

Spirit has also gazed longingly up into nighttime sky for meteorological
purposes.

"We're looking for any evidence of clouds forming at night, or fog, or
haze," Bell said. To do this job, nighttime shots are being taken using
the backdrop of stars - as well as Phobos and Deimos - to help pin down
atmospheric phenomena.

As the two moons slip by overhead, Spirit is getting a spectacular view.

Deimos looks pretty much like a star, far away. But Phobos is an eyeful,
Bell observed.

"You can clearly see that Phobos is an oblong, potato-shaped object in
the sky. It's not as big as the full moon, but it is still pretty decent
in size," Bell said. A soon-to-be-released image will show features on
the surface of Phobos, he said, "and this is with not much better than
human eye resolution!"

In fact, Phobos is so close and large enough, a person standing on Mars,
within a few minutes, would notice the moon moving, Bell said.

Shower times

Thanks to the rover's power levels, Bell said that a proposal is being
made to use Spirit to observe meteor showers this fall.

Just like here on Earth, the red planet also sweeps through areas of
space laden with comet debris. Scientists want to evaluate the flux of
these small particles streaming into the martian atmosphere.

"There are models that predict certain rates of meteors, and like on
Earth, there are shower times," Bell said. Spirit's nighttime powers
should help record that shower activity, he said.
Received on Wed 07 Sep 2005 07:05:42 PM PDT