Maven: a probe to discover the secrets of Mars’ atmosphere
Launched November 18th will tell us why the red planet has become barren and dry, and if a time it was really a living planet.
What happened to the atmosphere of Mars? There was a time, between three and four billion years ago, when the red planet was shrouded by clouds and dense gas as terrestrial ones, which allowed water to flow over its surface in large rivers and streams. Then something changed: the air has become more and more rarefied, to prevent water to exist in liquid form, thus turning the red planet, potential twin of Earth, in the cold and desolate expanse of rocks and stones we see today thanks to the images sent by the Rover.
To find out how this happened and why, was launched from Cape Canaveral on Monday the probe MAVEN, which stands for Mars Atmosphere and Volatile Evolution. The name already reveals its objectives: to determine the loss of volatile elements in the Martian atmosphere over time and to estimate the current rate of escape of molecules in space.
An hour after launch, just split off from the Atlas V rocket that brought in space, the spacecraft deployed its solar panels and is now on its way to Mars, which will reach in ten months in September 2014, going to support the already large fleet of satellites that are orbiting (in October India has also launched its own probe). Then it’s inserted into the upper atmosphere of the planet in order to study the phenomenology thanks to sophisticated electronic equipment.
Although composed almost entirely of carbon dioxide, the atmosphere is so tenuous that does not allow greenhouse gases (though probably present in the distant past) making the Martian climate to be hostile to life (barely reach the maximum and minimum spring temperatures are under one hundred degrees). The lack of ozone cannot offer protection from cosmic rays, sterilizing everything to the ground. Furthermore, the pressure is about sixty times lower than on land, so the water can remain only in the form of ice (the poles) or liquid, but in the bowels of the underground.
All conditions to study and understand well, in view of a future human mission, are scheduled for 2030 on paper. Meanwhile, MAVEN, which will remain in orbit until 2016, will collect data on the properties of the ionosphere, the composition of the gas, its magnetic field, the composition of the solar wind particles and their interactions with the weather.
Yeah, because scientists have any idea if they are made: between the various theoretical models developed, there is also what he sees as the solar radiation responsible for the loss of atmosphere (as shown in this video). Over millions of years, super photon energy emitted from the Sun would have ionized the atmospheric molecules, creating free electrons. These particles collide with the gas; they would split the bonds and provided enough energy to shoot it into deep space. If things went really well, MAVEN will confirm this in under a year.