High
atop Husband Hill within Gusev crater, the Spirit Mars rover is performing
nighttime astronomical duties.
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.
advertisement
