March 18, 2015 – NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, built by Lockheed Martin, has observed two unexpected phenomena in the Martian atmosphere: an unexplained high-altitude dust cloud and aurora that reaches deep into the Martian atmosphere.
The presence of the dust at orbital altitudes from about 93 miles (150 kilometers) to 190 miles (300 kilometers) above the surface was not predicted. Although the source and composition of the dust are unknown, there is no hazard to MAVEN and other spacecraft orbiting Mars.
“If the dust originates from the atmosphere, this suggests we are missing some fundamental process in the Martian atmosphere,” said Laila Andersson of the University of Colorado’s Laboratory for Atmospherics and Space Physics (CU LASP), Boulder, Colorado.
The cloud was detected by the spacecraft’s Langmuir Probe and Waves (LPW) instrument, and has been present the whole time MAVEN has been in operation. It is unknown if the cloud is a temporary phenomenon or something long lasting. The cloud density is greatest at lower altitudes. However, even in the densest areas it is still very thin. So far, no indication of its presence has been seen in observations from any of the other MAVEN instruments.
Possible sources for the observed dust include dust wafted up from the atmosphere; dust coming from Phobos and Deimos, the two moons of Mars; dust moving in the solar wind away from the sun; or debris orbiting the sun from comets. However, no known process on Mars can explain the appearance of dust in the observed locations from any of these sources.
MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) observed what scientists have named “Christmas lights.” For five days just before December 25, 2014 MAVEN saw a bright ultraviolet auroral glow spanning Mars’ northern hemisphere. Aurora, known on Earth as northern or southern lights, are caused by energetic particles like electrons crashing down into the atmosphere and causing the gas to glow.
“What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs – much deeper than at Earth or elsewhere on Mars,” said Arnaud Stiepen, IUVS team member at the University of Colorado. “The electrons producing it must be really energetic.”
The source of the energetic particles appears to be the sun. MAVEN’s Solar Energetic Particle instrument detected a huge surge in energetic electrons at the onset of the aurora. Billions of years ago, Mars lost a global protective magnetic field like Earth has, so solar particles can directly strike the atmosphere. The electrons producing the aurora have about 100 times more energy than you get from a spark of house current, so they can penetrate deeply in the atmosphere.
The findings are being presented at the 46th Lunar and Planetary Science Conference in The Woodlands, Texas.
MAVEN launched November 18, 2013 on a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida. The primary goal of NASA’s MAVEN mission is to reconstruct Mars’ climate history. MAVEN will provide information on how, and how fast, atmospheric gases are being lost to space today, and infer from those detailed studies what happened in the past.
The spacecraft arrived at Mars on September 21, 2014 and is four months into its one-Earth-year primary mission.
“The MAVEN science instruments all are performing nominally, and the data coming out of the mission are excellent,” said Bruce Jakosky of CU/LASP, Principal Investigator for the mission.
MAVEN is part of the agency’s Mars Exploration Program, which includes the Opportunity and Curiosity rovers, the Mars Odyssey and Mars Reconnaissance Orbiter spacecraft currently orbiting the planet.
NASA’s Mars Exploration Program seeks to characterize and understand Mars as a dynamic system, including its present and past environment, climate cycles, geology and biological potential. In parallel, NASA is developing the human spaceflight capabilities needed for its journey to Mars or a future round-trip mission to the Red Planet in the 2030’s.
MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics. CU/LASP provided two of MAVEN’s science instruments and also spearheads education and public outreach for the MAVEN mission, which has contributed roughly $300 million to Colorado’s economy.
Several CU-Boulder students work on the MAVEN science team, and there will be a number of additional CU-Boulder students working on MAVEN in the coming years. There are currently more than 100 students working on research projects at LASP, which provides hands-on training for future careers as engineers and scientists.
The spacecraft’s flight operations are controlled by a team at Lockheed Martin’s Mission Support Area near Denver, Colorado.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project. Partner institutions include Lockheed Martin, the University of California at Berkeley, and NASA’s Jet Propulsion Laboratory.