The new findings, published in the journal Geology, upend previous studies, which had estimated that the Red Planet's internal water stores were scanty at best -- something of a surprise, given that liquid water apparently flowed on the Martian surface long ago.
"It's been puzzling why past estimates for the planet's interior have been so dry," said study co-author Erik Hauri of the Carnegie Institution of Washington.
"This new research makes sense and suggests that volcanoes may have been the primary vehicle for getting water to the surface," Hauri was quoted as saying by LiveScience.
For their study, the scientists examined two Martian meteorites that formed in the planet's mantle, the layer under the crust. These rocks landed on Earth about 2.5 million years ago after being blasted off the planet by a violent impact.
Using a technique called secondary ion mass spectrometry, the team determined that the mantle from which the meteorites derived contained between 70 and 300 parts per million (ppm) of water. Earth's mantle, for comparison, holds roughly 50-300 ppm water, the researchers said.
The results, Hauri said, "suggest water was incorporated during the formation of Mars and the planet was able to store water in its interior during the planet
