Mauna Kea is an enormous, exinct volcano on Hawaii’s Big Island, and one of the best places on Earth to do astronomy (if you ask them, the best one). In fact, the summit of the mountain hosts one of the world’s most renowned observatories. What makes it so special, other than that it looks like this?
The atmosphere of a planet holds the keys to make it habitable, so we need to look at them to figure if exoplanets are habitable. They are too far to send probes to measure them directly like we do with Mars or Jupiter’s moons, but scientists can study them from right here, looking at how they block light.