Scientists have uncovered evidence of at least two billion years of volcanic activity on Mars, after analysing a meteorite from the red planet. Tom Lapen, a professor at the University of Houston in the US said, the findings offer new clues to how the planet evolved and insight into the history of volcanic activity on Mars. <br/><br/>The study published in the journal Science Advances said the finding confirms that some of the longest-lived volcanoes in the solar system may be found on the red planet. The study says, something slammed into the surface of Mars one million years ago, hitting a volcano or lava plain and the impact ejected rocks into space. Fragments of these rocks crossed Earth's orbit and fell as meteorites.<br/><br/>Analysis of different substances provides information about the age of the meteorite, its magma source, length of time in space and how long the meteorite was on Earth's surface, the study said.The meteorite, known as Northwest Africa 7635 and discovered in 2012, was found to be a type of volcanic rock called a shergottite. The largest Martian volcano, Olympus Mons, is nearly 27.3 kilometres high. That is almost triple the height of Earth's tallest volcano, Mauna Kea, at 10 kilometres.