Monday, November 18, 2013

New NASA Mars Mission Launches Today

We are in the midst of a storm here in Grand Marais.  It may be lessening now, but it still windy, snowing, and getting colder.  My power went out during the night and came back on mid-morning.  Yesterday it was windy and rainy, so I didn't go out hiking.  If the wind dies down, I'll try to get out

An hour from when I am typing these words, an Atlas V rocket will launch a satellite for a new Mars mission called MAVEN  (the Mars Atmosphere and Volatile Evolution spacecraft).

The Maven orbiter will study the planet's high atmosphere, to try to understand the processes that robbed Mars of most of its air.  Prior research shows that Mars once had a thick atmosphere made up of gases that supported the presence of liquid water at its surface.  Most of this atmosphere has been stripped away leaving some but very little air pressure. 

Scientists hypothesis that the most likely explanation for the loss of the Mars atmosphere is that solar wind - the  outflow of energetic particles from the Sun - has simply eroded gas molecules through time.  Our planet has a magnetic field that shields Earth and protects our atmosphere from the solar wind.  The planet Mars does not have a magnetic field. 

The launch happens at 1:28 pm today in Florida.  After lift off, the rocket's upper stage will release around 53 minutes into the flight, just at the edge of space.  After a couple of burns, the second stage will then release and the probe will begin its 10-month trip to Mars arriving next September 22nd. Once it arrives, the spacecraft will orbit at about 4,000 miles (6400 km) above the planet for a year, recording changes in its atmosphere.

Previous research conducted during other Mars missions shows that the atmosphere of our sister planet is composed mostly of carbon dioxide. Atmospheric pressure at the surface is only about 0.6% of the Earth's surface pressure, meaning any open liquid water would rapidly boil away.  The Martian landscape, though, retains channels that were evidently cut by abundant, flowing water - proof that the planet had a much denser atmosphere in the past.  The photo sequence below shows the path of water erosion on the surface of Mars.

Maven  will measure the rates at which different air molecules are stripped away today and determine what processes are responsible.  Scientists will then use these measurements to speculate what has happened during the last several billion years to change the planet from a warm and wet environment that may have potentially been habitable to life, to the present environment which is cold and life-less.  Maven also carries equipment to relay data to Earth from Curiosity and other Mars rovers

That primary mission lasts one Earth year (half a Mars year), after which the science team will need additional funding to continue their investigations.  NASA will keep operating Maven long into the future as a data-relay platform for surface rovers like Curiosity.  Scientists believe there is enough  fuel to keep the vehicle flying for years. As a reference, Mars Odyssey was launched in 2001 and is still operating today.


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