New research using observations from NASA's Mars Reconnaissance Orbiter indicates that Arsia Mons, one of the largest volcanos on Mars, actively produced lava flows until about 50 million years ago. This wide view of the volcano is from the Viking 1 Orbiter. The last volcanic activity there ceased about 50 million years ago -- around the time of Earth's Cretaceous-Paleogene extinction, when large numbers of our planet's plant and animal species (including dinosaurs) went extinct. Credit: NASA/JPL/USGS #volcano #dinosaurs #mars #orbiter #interesting #beautiful #orange #planet #extinct