From Higher Perspective, March 8, 2015
An ocean once covered half of the northern hemisphere of Mars, according to NASA scientists. This makes it far more likely that the red planet was once blue – and teeming with alien life.
The ocean covered more than one fifth of the planet’s surface, making it about as large as the Atlantic Ocean. In total, it held 20 million cubic kilometers of water. That’s a bit more than what is held in the arctic ocean.
NASA unveiled their evidence for the primitive ocean on Thursday, and emerging with that evidence is a wet world with streams, rivers, and lakes soon after it was formed over four and a half billion years ago.
Only ten years ago, scientists believed that the presence of water was more random and erratic, likely in liquid form only occasionally and never in standing oceans.
“A major question has been how much water did Mars actually have when it was young and how did it lose that water?” said Michael Mumma, a senior scientist at NASA Goddard Space Flight Center in Maryland.
Martian water is like that found on Earth – made of two hydrogen atoms and one oxygen atom. Another form of water made with a heavy isotope of hydrogen called deuterium has also been found. Over time, the lighter form of water was lost into space, passing slowly through the planet’s thin atmosphere. Only the heavier water remained. In this way, scientists have been able to estimate how much water originally existed on the planet.
One thing is for sure – this discovery will only ramp up speculation about the potential that life existed, or exists, on our neighboring planet.
Image above: An artist’s impression of the ancient ocean on Mars, which lasted for billions of years more than was previously thought. Credits: Mars Geronimo Villanueva/Nasa