Gravity mapping data from a European Mars mission has revealed information about the Red Planet's volcanic history, researchers say.
The European Space Agency's Mars Express made the measurement from altitudes of between 170 and 200 miles above the Tharsis region and its so-called volcanic bulge, a release from ESA's Paris headquarters reported Thursday.
The Tharsis bulge includes Olympus Mons -- the tallest volcano in the solar system at miles high -- and three smaller Tharsis Montes that are evenly spaced in a row.
The region is thought to have been volcanically active until 100 million to 250 million years ago, relatively recent on a geological timescale, researchers said.
Gravity measurements revealed different density of lava beneath the three Tharsis Montes volcanoes.
"Combined with the varying height of the volcanoes, we can say that Arsia Mons is the oldest, then Pavonis Mons formed and finally Ascraeus Mons," researcher Mikael Beuthe of the Royal Observatory of Belgium said.
Volcanic activity is considered a key factor in the formation of features on the Martian surface, researchers said.
"These results show that data on the Mars interior are key to understanding the evolution of the Red Planet," Olivier Witasse, ESA Mars Express project scientist, said. (c) UPI