Clue To Extreme Change In Martian Atmosphere Revealed

Now they know why.

Solar winds emitted from the sun basically give gas ions sitting in Mars’ upper atmosphere enough of an energy kick that they are able to escape the planet’s gravitational pull and leak out into outer space.

Finally though, at the news briefing and in a papers published today in Geophysical Research Letters and Science, the team of researchers illustrate how the atmosphere was essentially blown away – and took the water with it.

The blue and red areas are the spots on Mars still shielded by a partial magnetic field. Seventy five percent is lost where the solar wind flows behind Mars called the tail, 25 percent is lost above the Martian poles in a “polar plume”, and a minor loss in a cloud of gas surrounding Mars. The question has been: How did Mars turn into the dry, dusty, and chilly barren planet? During that relatively short epoch the lakes and rivers on Mars, of which geologic evidence remains today, would have frozen and evaporated. The consequences for any life that might have existed nearly certainly would have been disastrous.

Mars too used to have a magnetic field, but about 3.7 billion years ago its core began to freeze and solidify which caused the field to fade out. The culprit? Solar wind – particularly the types of energetic blasts emitted by the sun during periods of unrest. Particles of air can also be knocked into space through collisions with incoming solar wind particles, like billiard balls. According to the Washington Post, lucky Earth has one thing that Mars does not: a strong magnetic field, which serves as a barrier to those solar winds.

Considering it was only yesterday that we wrote about the White House’s plans for potentially damaging solar storms, this news might sound alarming for all of us here on Earth, but there is very little reason for concern.

Announcing “key science findings” about the MAVEN mission to study the atmosphere of Mars, NASA officials quoted Bob Dylan Thursday, saying “The answer, my friend, is blowing in the wind”.

“With every spacecraft mission, you always discover a few things that are a complete surprise”, said mission co-investigator Dave Brain from CU-Boulder’s Laboratory for Atmospheric and Space Physics, or LASP, in an interview.

On October 28, NASA Administrator Charles Bolden stated that US President Barack Obama remains committed to a 2030 manned mission to Mars. But there’s no rush.

A younger Mars may have lost its atmosphere at a more rapid pace when the sun churned out more violent and frequent storms. A mystery remains regarding exactly how – and when – its core cooled and it stopped generating its magnetic field, enabling solar winds to slowly sweep away the atmosphere over eons and making it unable to sustain the massive ocean that once covered much of its northern hemisphere, Jakosky said.

It appears that when Mars is directly hit by a solar storm, the atmosphere is torn apart.

Today, it is about 100 times thinner than Earth’s, and made up of about 96 per cent carbon dioxide, less than two per cent argon, less than two per cent nitrogen, and less than one per cent other gases.