If
you ever wondered what it would be like to stand on Mars and view the night
sky, two robots have beat you wheels down.
In "Backyard Astronomy from Mars" carried in the August issue of Sky &
Telescope magazine (soon to hit newsstands), author Jim Bell details use of
the Spirit and Opportunity Mars rovers to carry out nighttime observations. He is
an astronomer and planetary scientist at Cornell University in Ithaca, New York, and is the leader of the Mars Exploration Rover Panoramic Camera (Pancam)
team.
In
the article, Bell discusses astronomical sight-seeing utilizing Spirit, fresh
from a laborious trek up Husband Hill within the Columbia Hills at the robot's
Gusev Crater exploration zone.
Thanks
to a dust devil blowing away particles that had fallen onto Spirit's solar
panels, the intrepid rover became power rich. "We had enough power to run the
rover's computer and cameras, and their associated heaters, at night," Bell explains.
"It
was an embarrassment of riches," Bell writes. "Several of us on the rover team
are astronomers, either professionals or amateurs, and we have always been
intrigued by the prospect of stargazing from the surface of another world."
Novel observations
Admittedly,
Bell relates, there were numbers of constraints using the robot--and a need to
justify use of a $400 million rover for astronomical observations. "It would be
stone-knives and bear-skins backyard astronomy--but from Mars!"
Despite
the obstacles, a set of novel astronomical observations were made using Spirit.
For example, the two Mars moons--Phobos and Deimos--were pictured, with camera
filters applied to yield new data about the surface compositions of the red
planet's natural satellites.
Stars
with known brightnesses were also imaged, allowing researchers to look for
evidence of nighttime dust or water-ice clouds wafting about in the thin
martian atmosphere.
Long
exposure takes by Spirit captured star trails. These images recorded linear
streaks, dots, and splotches created by cosmic rays striking the camera's
sensitive detectors. The observations can help validate meteor-shower
predictions, Bell says, giving scientists useful clues as to the rate of
impacts of small meteoroids on the planet.
"Finally,
we obtained twilight-sky images from both Spirit and Opportunity," Bell writes. "These include some spectacular views of sunrises and sunsets - useful for
analyzing how dust is distributed vertically in the Martian atmosphere, but also
just plain beautiful."
During
the latter part of 2005, the Opportunity Mars rover on the other side of the
planet from Spirit caught Earth and Jupiter rising together before dawn in the
eastern sky of Meridiani Planum.
"What
an amazing experience," Bell notes, "to be living on one planet and taking
pictures of ourselves from the surface of another!"
New campaigns possible
As
for the future, Bell told SPACE.com via email that Mars scientists are mostly
worried about keeping Spirit and Opportunity alive through the coming martian
winter.
"However,
if we are fortunate enough to survive and continue to operate during a third
martian summer, we may be able to initiate new twilight or night-time astronomy
campaigns on one or both vehicles," Bell explained. These observations could
provide additional information on morning or evening clouds and atmospheric
dynamics, or astrometric data to further refine the orbits of Phobos and
Deimos, he said.
Also,
the rovers could be used to perform a longer, more sensitive search for meteors
in the martian atmosphere, Bell added, compared to the limited search that was performed
in 2005.
Furthermore,
Bell said, additional information on the martian surface's harsh cosmic ray
environment--which the rover camera system is very sensitive to during night-time
imaging observations -- could be used to help the imaging investigations on future
missions like the upcoming NASA Phoenix lander and Mars Science Laboratory
missions...to help design more robust cameras or electronics.
Check
out Sky and Telescope for more.
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