[meteorite-list] MAVEN Mission Provides Its First Look at Martian Upper Atmosphere

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?feature=4334

NASA Mission Provides Its First Look at Martian Upper Atmosphere
Jet Propulsion Laboratory
October 14, 2014

NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has provided 
scientists their first look at a storm of energetic solar particles at 
Mars, produced unprecedented ultraviolet images of the tenuous oxygen, 
hydrogen, and carbon coronas surrounding the Red Planet, and yielded a 
comprehensive map of highly variable ozone in the atmosphere underlying 
the coronas.

The spacecraft, which entered Mars' orbit Sept. 21, now is lowering its 
orbit and testing its instruments. MAVEN was launched to Mars in November 
2013, to help solve the mystery of how the Red Planet lost most of its 
atmosphere.

"All the instruments are showing data quality that is better than anticipated 
at this early stage of the mission," said Bruce Jakosky, MAVEN principal 
investigator at the University of Colorado, Boulder. "All instruments 
have now been turned on -- although not yet fully checked out -- and are 
functioning nominally. It's turning out to be an easy and straightforward 
spacecraft to fly, at least so far. It really looks as if we're headed 
for an exciting science mission."

Solar energetic particles (SEPs) are streams of high-speed particles blasted 
from the sun during explosive solar activity like flares or coronal mass 
ejections (CMEs). Around Earth, SEP storms can damage the sensitive electronics 
on satellites. At Mars, they are thought to be one possible mechanism 
for driving atmospheric loss.

A solar flare on Sept. 26 produced a CME that was observed by NASA satellites 
on both sides of the sun. Computer models of the CME propagation predicted 
the disturbance and the accompanying SEPs would reach Mars on Sept. 29. 
MAVEN's Solar Energetic Particle instrument was able to observe the onset 
of the event that day.

"After traveling through interplanetary space, these energetic particles 
of mostly protons deposit their energy in the upper atmosphere of Mars," 
said SEP instrument lead Davin Larson of the Space Sciences Laboratory 
at the University of California, Berkeley. "A SEP event like this typically 
occurs every couple weeks. Once all the instruments are turned on, we 
expect to also be able to track the response of the upper atmosphere to 
them."

The hydrogen and oxygen coronas of Mars are the tenuous outer fringe of 
the planet's upper atmosphere, where the edge of the atmosphere meets 
space. In this region, atoms that were once a part of carbon dioxide or 
water molecules near the surface can escape to space. These molecules 
control the climate, so following them allows us to understand the history 
of Mars over the last four billion years and to track the change from 
a warm and wet climate to the cold, dry climate we see today. MAVEN observed 
the edges of the Martian atmosphere using the Imaging Ultraviolet Spectrograph 
(IUVS), which is sensitive to the sunlight reflected by these atoms.

"With these observations, MAVEN's IUVS has obtained the most complete 
picture of the extended Martian upper atmosphere ever made," said MAVEN 
remote sensing team member Mike Chaffin of the University of Colorado, 
Boulder. "By measuring the extended upper atmosphere of the planet, MAVEN 
directly probes how these atoms escape to space. The observations support 
our current understanding that the upper atmosphere of Mars, when compared 
to Venus and Earth, is only tenuously bound by the Red Planet's weak gravity."

IUVS also created a map of the atmospheric ozone on Mars by detecting 
the absorption of ultraviolet sunlight by the molecule.

"With these maps we have the kind of complete and simultaneous coverage 
of Mars that is usually only possible for Earth," said MAVEN remote sensing 
team member Justin Deighan of the University of Colorado, Boulder. "On 
Earth, ozone destruction by refrigerator CFCs is the cause of the polar 
ozone hole. On Mars, ozone is just as easily destroyed by the byproducts 
of water vapor breakdown by ultraviolet sunlight. Tracking the ozone lets 
us track the photochemical processes taking place in the Martian atmosphere. 
We'll be exploring this in more complete detail during MAVEN's primary 
science mission."

There will be about two weeks of additional instrument calibration and 
testing before MAVEN starts its primary science mission. This includes 
an end-to-end test to transmit data between NASA's Curiosity rover on 
the surface of Mars and Earth using the MAVEN mission's Electra telecommunications 
relay. The mission aims to start full science gathering in early to mid-November.

MAVEN's principal investigator is based at the University of Colorado's 
Laboratory for Atmospheric and Space Physics. The university provided 
two science instruments and leads science operations, as well as education 
and public outreach, for the mission. The University of California at 
Berkeley's Space Sciences Laboratory also provided four science instruments 
for the mission. NASA's Goddard Space Flight Center in Greenbelt, Maryland, 
manages the MAVEN project and provided two science instruments for the 
mission. Lockheed Martin built the spacecraft and is responsible for mission 
operations. NASA's Jet Propulsion Laboratory in Pasadena, California, 
provides navigation and Deep Space Network support, as well as the Electra 
telecommunications relay hardware and operations.

For more about MAVEN, visit:

http://www.nasa.gov/maven


Media Contact

Nancy Jones / Bill Steigerwald
Goddard Space Flight Center, Greenbelt, Maryland
301-286-0039 / 301-286-5017
nancy.n.jones at nasa.gov / william.a.steigerwald at nasa.gov 

Dwayne Brown
NASA Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov 

Guy Webster
Jet Propulsion Laboratory, Pasadena, California
818-354-6278
guy.webster at jpl.nasa.gov 

2014-351