Nasa has finally discovered what caused Mars to become a barren, lifeless world.
In a much-anticipated announcement, researchers have revealed that our sun robbed the red planet of its water and atmosphere.
And the process is still happening today, with Mars’ upper atmosphere slowly being eroded by solar winds.
The space agency said the discovery could provide new insights into Mars’ history, evolution, and, possibly, the planet’s habitability.
Mars’ atmosphere is about 100 times thinner than Earth’s, and made up mostly of carbon dioxide.
However, around 4.2 billion years ago, the red planet had a much thicker atmosphere, making wet and warm – similar to Earth.
But something happened to its protective magnetic shield, causing the once oceanic world to become a dry, barren planet incapable of supporting life.
This caused solar wind to bombard the planet, stripping it of its atmosphere.
Solar wind has a temperature greater than one million°C and is so hot that the sun’s gravity can’t hold it down.
It flows away in all directions traveling 500 miles per seconds (800 km/s).
Every planet in the solar system is immersed in this gusty breeze of charged particles.
Today, Mars’ thin atmosphere and distance from the sun mean that Mars is much colder than Earth.
The average temperature is about -80°F (-60°C), although it can vary from -195°F (-125°C) near the poles during the winter.
The findings were made by the Maven mission, which has been orbiting the red planet, piecing together clues about what happened to all the air on Mars.
The probe has helped Nasa determine the rate at which the Martian atmosphere currently is losing gas to space as a result of the solar wind.
The findings reveal that the erosion of Mars’ atmosphere increases significantly during solar storms.
‘Mars appears to have had a thick atmosphere warm enough to support liquid water which is a key ingredient and medium for life as we currently know it,’ said John Grunsfeld, astronaut and associate administrator for Nasa.
‘Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmosphere.
‘Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key question that is being addressed in Nasa’s journey to Mars.’
Maven measurements indicate that the solar wind strips away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second.
Maven scientist Dave Brain told reporters he can’t help but imagine hamburgers shooting out of the Martian atmosphere.
At the current rate, Mars will lose its entire atmosphere in a few billion years.
‘Like the theft of a few coins from a cash register every day, the loss becomes significant over time,’ said Bruce Jakosky, Maven principal investigator at the University of Colorado, Boulder.
‘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.’
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