New research indicates Mars could have once had a surface ocean larger than the Earth's Atlantic Ocean.

According to Space.com, authors of a study published in the journal Science believe Mars' ocean once covered one-fifth of its surface. But determining how Mars lost its water appears to be a separate issue.

"Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space," study lead author Geronimo Villanueva, a scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a press release. "With this work, we can better understand the history of water on Mars."

Thanks to several discoveries in recent years, NASA has determined the Red Planet likely once had water. Therefore saying Mars once could have hosted some sort of life forms is not a stretch.

"With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer," study second author Michael Mumma, a senior scientist at Goddard, said in the release.

Mars' atmosphere is quite thin and the scientists believe that could mean water evaporation on Mars would have been all the easier.

"A major question has been how much water did Mars actually have when it was young and how did it lose that water?" Mumma told the Guardian. "We now know Mars was wet for a much longer time than we thought before.

"Now we see that Mars must have been wet for a period even longer."