Though it might not seem like it today, Mars once had an atmosphere thick enough to sustain liquid water on the surface. It isn’t entirely clear what happened over the last four billion years that changed those conditions, but NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter will attempt to find out by studying what is left of the red planet’s upper atmosphere. MAVEN reached Mars on September 21 and though it is still making adjustments to its orbit and turning instruments on, it has already sent back the first data describing the variable composition of the upper atmosphere.
If you are wondering what MAVEN is well here is a brief run down…Ahem. Around four billion years ago Mars had an atmosphere thick enough to sustain liquid water on the planet’s surface; a critical component for life. Today, the atmosphere is all but gone – as is the water. What happened to cause such a drastic change? NASA hopes to find out. The Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter will launch today, November 18, and will begin its science mission when it reaches the red planet in September 2014.
MAVEN launched at 1:28 EST from Cape Canaveral Air Force Station in Florida. Due to weather, there were some concerns that the launch would not proceed as planned. If MAVEN had not gotten off the ground during the 20 day launch window, NASA would not be able to try again until 2016 when the planets will once again be so favorably aligned. The MAVEN mission was exempted from the US government shutdown in October due to the precise launch time required. MAVEN launched via an Atlas V rocket. Currently, MAVEN has deployed the solar arrays that will power it on the journey to Mars.
Using eight sensors in three categories, MAVEN will explore the upper atmosphere and ionosphere of Mars. The Particles and Fields Package is composed of six sensors to explore how solar activity affects the atmosphere. Those sensors are Solar Wind Electron Analyzer, Solar Wind Ion Analyzer, Suprathermal and Thermal Ion Composition, Solar Energetic Particle, Langmuir Probe and Waves, and the Magnetometer. The Remote Sensing Package consists of the Imaging Ultraviolet Spectrograph and will characterize the atmosphere. The Neutral Gas and Ion Mass Spectrometer will distinguish the atmospheric neutral ions and identify any isotopes that may be present.
Also onboard MAVEN is a DVD that represents a very successful public outreach endeavor. A poetry contest had over 12,000 submissions for haikus about Mars. Over 1,100 of those received at least two votes and will be included on the DVD. There is also a list of over 100,000 names of MAVEN supporters. The DVD’s label was the 1st place winner of the student artwork competition. A Kindergarten class collectively won the honor, though images of all of the 377 submissions will also be included on the DVD.
MAVEN was manufactured by Lockheed Martin. The solar-powered spacecraft is 37.5 feet (11.4 meters) long and currently weighs 5622 pounds (2550 kilograms) as it is fueled for launch. Its antenna will allow it to transmit back to Earth twice a week during its 1-Earth-year-long primary science mission from Mars. During its mission, it will orbit Mars elliptically, ranging from 93 miles (150 km) to 3728 miles (6000 km) from the surface. Five times throughout the mission, MAVEN will perform a “deep dip†and travel only 77 miles (125 km) off the surface to collect information about the lower atmosphere of Mars.
After MAVEN is launched, the Jet Propulsion Laboratory in Pasadena, California will be responsible for navigation and communication transmission. Overall mission management comes from NASA’s Goddard Space Flight Center, which is a first for that facility. The principal investigator for the MAVEN mission is Dr. Bruce Jakosky. Jakosky comes from the University of Colorado Laboratory for Atmospheric and Space Physics (UC/LASP) which made several of the sensory instruments.
Anyway, as I was saying….
A contributing factor to the loss of the martian atmosphere is believed to be high-speed solar energetic particles (SEP). During times of solar activity, such as during flares or coronal mass ejections, SEPs can shoot out from the sun and potentially help strip away the atmosphere of Mars. MAVEN has an instrument to detect and study SEPs and wasted no time. Days after MAVEN entered orbit, a solar flare kicked out SEPs that reached Mars on September 29.
“After traveling through interplanetary space, these energetic particles of mostly protons deposit their energy in the upper atmosphere of Mars,” Davin Larson said in a press release. Larson is the SEP instrument lead. “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 upper atmosphere is the final barrier that prevents this material from escaping into space. It is very thin, and held together by the red planet’s gravity, which is only 38% as strong as Earth’s.
Using the Imaging Ultraviolet Spectrograph (IUVS), the team was able to construct an ozone map (pictured above) of the carbon, oxygen, and hydrogen within the upper atmosphere; the three products of the breakdown of carbon dioxide and water. Tracking these molecules can help scientists understand how the atmosphere is being stripped away, and thus how the conditions of the surface of Mars have changed so drastically over time. The map revealed to scientists that the atmosphere of Mars is highly variable.
“With these maps we have the kind of complete and simultaneous coverage of Mars that is usually only possible for Earth,” added MAVEN researcher Justin Deighan. “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.â€
This commissioning phase, where MAVEN is making adjustments and testing out instruments, will continue for another two weeks. In the first week of November, MAVEN will begin the primary science mission which is expected to last for one Earth year.
– Credit and Resource –
MAVEN Returns First Light Data From Mars
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