WEBVTT FILE 1 00:00:09.959 --> 00:00:13.963 Billions of years ago Mars was able to have highly explosive volcanism 2 00:00:13.963 --> 00:00:18.168 and it's not just a one-off but we had many episodes of highly explosive volcanism 3 00:00:18.168 --> 00:00:20.487 in a sort of short geologic window 4 00:00:20.754 --> 00:00:25.208 Two folks found these things that look like impact craters in Arabia Terra 5 00:00:25.208 --> 00:00:28.194 but they're missing some features and they have some different features that 6 00:00:28.194 --> 00:00:32.115 actually make them look more like volcanic caldera formed from explosions 7 00:00:41.157 --> 00:00:46.579 On Earth we can't actually see this far in the past in many places because we 8 00:00:46.579 --> 00:00:50.683 have erosion on Earth so we don't have access to a great geologic record for 9 00:00:50.700 --> 00:00:54.838 three billion years ago on Earth. On Mars, we can see that 10 00:00:55.622 --> 00:00:59.209 We're trying to understand just how large explosions 11 00:00:59.209 --> 00:01:04.297 or large lava flows on places like Earth but also other planets might affect the climate 12 00:01:08.384 --> 00:01:14.941 So we know from just the last century that very large volcanoes do have a climate impact 13 00:01:14.941 --> 00:01:18.628 This tells us something really important about the history of Mars 14 00:01:18.628 --> 00:01:21.297 and in turn the history of just planets in the solar system