Stargazers have long been obsessed with the question of whether there is life on Mars. The first man to map Mars, Italian astronomer Giovanni Schiaparelli, first triggered life on Mars mania after spotting long linear features, he dubbed “canals”. Now we know Mars really was once criss-crossed with rivers twice as wide as any on Earth, making the chance of finding residual alien life forms far more likely.
Satellite images of Mars shows water once freely flowed on its surface for far longer than expected.
Scientists studied more than 200 ancient riverbeds on the Red Planet’s surface and their findings suggest that Mars’ rivers were filled with water only a billion years ago.
This is least a billion years later than previous estimates – and the shock finding will lead to a re-writing of the history of Mars.
The discovery will also make the complex task of mapping the ancient Martian climate all the more difficult.
Dr Edwin Kite, of the University of Chicago said: ”It is already hard to explain rivers or lakes based on the information we have.
“This makes a difficult problem even more difficult.”
Space scientists have long been aware of the ancient riverbeds that scarring the surface of Mars, but how it had water at its surface has never ben understood.
Mars has had a very think atmosphere throughout its history and only received a third of the sunlight of present-day Earth.
And these factors should not be sufficient to retain liquid water at its surface.
To understand how Martian rivers even existed, scientists analysed satellite photographs of more than 200 ancient Martian riverbeds.
The researchers then calculated the amount of water running through them using multiple methods, including measuring the size of the Martian river channels.
And scientists discovered there was intense run-off in these channels approximately one billion years-ago.
In total, three to 20 kilograms of water flowed through per squared metre daily, making the rivers larger than anything found on Earth.
Space scientists previously believed the Martian atmosphere disappeared approximately 4 billion years ago, triggering a gradual drying out of the planet.
The new study suggests this potentially happened billions of years later than these estimates.
Dr Kite also speculated it is also possible the climate had an ”on/off” switch, which tipped back and forth between dry and wet cycles.
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