June 14 (Xinhuanet) — Mars was once covered by an ocean several miles deep according to a new research by a team of Canadian and American scientists, which will be released in the journal Nature Thursday. The red planet, they said, had once been a deep blue, just like Earth.
The University of Toronto’s Jerry Mitrovica and his colleagues together with scientists from University of California-Berkeley reassessed and reinterpreted data about the topography of the Red Planet collected over the years by spacecraft visiting Mars.
The research focuses on a large plain surrounding Mar’s north pole that appears to be a sediment-filled ocean basin. But Martian topography mapping revealed the basin’s shorelines vary in elevation by more than a mile, rising and falling like a wave with several thousand miles from one peak to the next. Because shoreline elevations on Earth are typically constant, many experts dismiss the idea Mars once had oceans.
Experts have debated the issue since the 1970s, when the Viking spacecraft located the features.
“This gets us all on the same page. This debate about whether these oceans existed, clearly it’s an important debate and one of the main issues people were trying to resolve,” Mitrovica said.
The researchers believe that Mars’s poles, along with the axis the planet spins on, have moved about 1,850 miles (3,000 kilometers) during the past two or three billion years.
“When the spin axis moves relative to the surface, the surface deforms, and that is recorded in the shoreline,” said co-author Michael Manga, professor of earth and planetary science at the University of California, Berkeley.
The team also tried to figure out where all the water that was held in the ancient oceans went. Their calculations showed it couldn’t all have evaporated into space. This means it must have drained downward, beneath the surface of the planet. It is probably still there today — as ice, researchers said.