That will conclude our live coverage of today's announcement from Nasa on Mars' atmosphere. Here's all you need to know on today's events from Nick Allen in Washington:
The sun destroyed the atmosphere of Mars robbing the planet of what might once have been an environment replete with water and the conditions for life, Nasa said today.
Announcing the findings of its Maven probe which has been orbiting the Red Planet for the last year, the space agency said the once-thick atmosphere was blown away by the solar wind between 4.2 billion and 3.7 billion years ago.
Until that time water appeared to have been "abundant and active" on Mars, Nasa said.
Only one per cent of the Martian atmosphere remains and Maven found it is being stripped away at the rate of one quarter pound of gas per second.
The solar wind normally travels at one million miles per hour and Earth has a strong global magnetic field which shields it.
However, Mars' magnetic field shut down billions of years ago leaving it exposed at an earlier period in the life of the sun when solar storms were more extreme.
Nasa said the planet had been hit by "dense bubbles of extremely energetic particles" from the sun, which sometimes doubled the speed of the solar wind up to two million miles per hour.
That increased the rate at which Mars lost its atmosphere by a factor of 10 to 20.
Last Christmas, Maven observed a solar storm which was described as the equivalent of a large nuclear weapon hitting Mars every hour, but the storms billions of years ago would have been even stronger.
The recent solar storm led to a five-day Martian version of the Northern Lights.
From the surface a blue aurora would have been visible across much of the northern hemisphere.
Nick Schneider, a Nasa planetary scientist, said: "What we witnessed last Christmas was this aurora that engulfed the whole northern atmosphere as far as we can tell, something that just doesn’t happen on Earth."
The documenting of the loss of the Martian atmosphere shows how a planet that was once like Earth turned into a cold, dry desert.
Bruce Jakosky, principal investigator on the Maven project, said: "Like the theft of a few coins from a cash register every day the loss becomes significant over time.
"We've seen that the atmospheric erosion increases significantly during solar storms so we think the loss rate was much higher billions of years ago when the sun was young and more active.
"The single question we're really trying to get at is did the Mars climate change by loss to space or by some other process? What this tells us is loss through space has been an important process."
Michael Meyer, lead scientist of Nasa's Mars Exploration Program, said: "To answer the question of what happened to Mars' atmosphere, I'll quote Bob Dylan - the answer, my friend, is blowin' in the wind."
