NASA鈥檚 MAVEN spacecraft has provided scientists their first look at a storm of energetic solar particles at Mars and produced unprecedented ultraviolet images of the tenuous oxygen, hydrogen and carbon coronas surrounding the Red Planet, said 麻豆免费版下载 Professor Bruce Jakosky, the mission鈥檚 principal investigator.
In addition, the new observations allowed scientists to make a comprehensive map of highly variable ozone in the Martian atmosphere underlying the coronas, he said. The spacecraft entered Mars鈥� orbit Sept. 21 and is in the process of lowering its orbit and testing its instruments. The $671 million Mars Atmosphere and Volatile EvolutioN mission, or MAVEN, was launched toward Mars on Nov. 18, 2013, to help solve the mystery of how the Red Planet lost most of its atmosphere.
鈥淓verything is performing well so far,鈥� said Jakosky of CU-Boulder鈥檚 Laboratory for Atmospheric and Space Physics. 鈥淎ll of the instruments have now been turned on, and although they are not yet fully checked out, they are functioning nominally.
鈥淎ll the instruments are showing data quality that is better than anticipated at this early stage of the mission,鈥� said Jakosky, also a professor in CU-Boulder鈥檚 geological sciences department. 鈥淭he spacecraft is performing beautifully. It鈥檚 turning out to be an easy and straightforward spacecraft to fly, at least so far. It really looks as if we鈥檙e headed for an exciting science mission.鈥�
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 successfully predicted the disturbance and the accompanying SEPs would reach Mars on Sept. 29.
鈥淎fter traveling through interplanetary space, these energetic particles, mostly protons, deposit their energy in the upper atmosphere of Mars,鈥� said SEP instrument lead Davin Larson of the Space Sciences Laboratory at the University of California, Berkeley. 鈥淎 SEP event like this typically occurs every couple of weeks. Once all the instruments are turned on, we expect to also be able to track the response of the upper atmosphere to them.鈥�
The hydrogen and oxygen coronas of Mars are the tenuous outer fringe of the planet鈥檚 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, according to MAVEN scientists.
Water and carbon dioxide control the climate, so following them allows scientists 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 present today. MAVEN observed the edges of the Martian atmosphere using the CU-Boulder-built Imaging Ultraviolet Spectrograph (IUVS), which is sensitive to the sunlight reflected by the atoms.
鈥淲ith these observations, MAVEN鈥檚 IUVS has obtained the most complete picture of the extended Martian upper atmosphere ever made,鈥� said IUVS team member and CU-Boulder doctoral student Mike Chaffin of the Department of Astrophysical and Planetary Sciences. 鈥淏y 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 planet鈥檚 weak gravity.鈥�
IUVS also helped scientists create a map of the atmospheric ozone on Mars by detecting the absorption of ultraviolet sunlight by the molecule. 鈥淲ith these maps we have the kind of complete and simultaneous coverage of Mars that is usually only possible for Earth,鈥� said CU-Boulder Research Associate Justin Deighan, an IUVS team member from LASP. 鈥淥n 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 broken down by ultraviolet sunlight.
鈥淭racking the ozone lets us track the photochemical processes taking place in the Martian atmosphere,鈥� said Deighan. 鈥淲e鈥檒l be exploring this in more complete detail during MAVEN鈥檚 primary science mission.鈥�
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 of relaying data between NASA鈥檚 Curiosity rover on the surface of Mars and Earth using the MAVEN mission鈥檚 Electra telecommunications relay. The mission is aiming to start science in early to mid-November.
CU-Boulder provided two science instruments and leads science operations, as well as education and public outreach, for the MAVEN mission, which has contributed roughly $300 million to Colorado鈥檚 economy. UC Berkeley鈥檚 Space Sciences Laboratory also provided four science instruments for the mission.
NASA鈥檚 Goddard Space Flight Center in Greenbelt, Md., manages the MAVEN project and provided two science instruments for the mission. Lockheed Martin of Littleton, Colo., built the spacecraft and is responsible for mission operations. NASA鈥檚 Jet Propulsion Laboratory in Pasadena, Calif., provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.
For more information about MAVEN visit or .
Contact:
Bruce Jakosky, 303-492-8004
bruce.jakosky@colorado.edu
Justin Deighan, 303-735-0542
justin.deighan@colorado.edu
Michael Chaffin, 303-517-0319
michael.chaffin@colorado.edu
Jim Scott, CU-Boulder media relations, 303-492-3114
jim.scott@colorado.edu
