Somewhere around four billion years ago, volcanism started picking up on Mars. Scientists say that most part of the Tharsis bulge, the largest volcanic region in Mars, must have formed by 3.7 Gya (in Geology, Gya means Giga years ago, or billion years ago). But this was by no means the end of volcanic activity in the region, or on the planet. Lava and ash from newer eruptions continued to bury the older volcanoes over the years – it is said that the base of certain smaller, but ancient, volcanoes in the Tharsis region, called Tharsis tholi, lie about four kilometres below the current Martian surface! Intense volcanic activity on Mars continued till about 3 billion years ago, which was then followed by smaller isolated eruptions. It was believed until recently that volcanoes on Mars are presently inactive.
But thanks to the photographs taken by the European Space Agency’s (ESA) Mars Express Orbiter in 2004, scientists have evidence that Olympus Mons, the largest volcano on Mars, erupted somewhere between 1.1- and 2 million years ago. This meant that the mountain was quite young, in geological terms, and may still be active! More exciting news came this year with scientists finding a dark area in the Elysium region of Mars, something that might be a relatively fresh volcanic deposit of ash and rock. Based on this, scientists now believe that the Red Planet may have been volcanically active as recently as 53,000 years ago!
Picture Credit : Google
