MAVEN Spacecraft Returns First Mars Observations
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has obtained
its first observations of the extended upper atmosphere surrounding Mars.
The Imaging Ultraviolet Spectrograph (IUVS) instrument obtained these
false-color images eight hours after the successful completion of Mars orbit
insertion by the spacecraft at 10:24 p.m. EDT Sunday, Sept. 21, after a 10-month
journey.
The image shows the planet from an altitude of 36,500 km in three ultraviolet
wavelength bands. Blue shows the ultraviolet light from the sun scattered from
atomic hydrogen gas in an extended cloud that goes to thousands of kilometers
above the planet’s surface. Green shows a different wavelength of ultraviolet
light that is primarily sunlight reflected off of atomic oxygen, showing the
smaller oxygen cloud. Red shows ultraviolet sunlight reflected from the planet’s
surface; the bright spot in the lower right is light reflected either from polar
ice or clouds.
The oxygen gas is held close to the planet by Mars’ gravity, while
lighter hydrogen gas is present to higher altitudes and extends past the edges
of the image. These gases derive from the breakdown of water and carbon dioxide
in Mars’ atmosphere. Over the course of its one-Earth-year primary
science mission, MAVEN observations like these will be used to determine the
loss rate of hydrogen and oxygen from the Martian atmosphere. These
observations will allow us to determine the amount of water that has
escaped from the planet over time.
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