The summit of Mauna Kea feels like another planet. The air is thin. Nothing grows there. The cinder cones, remnants of past eruptions, seem to float in the sea of clouds. The sterile white domes of the observatories look decidedly futuristsic. The only things detracting from this feeling are the tourists and the cars that brought them.
But the summit of Mauna Kea does not just look like another planet. It is the closest you can get to the environment of another planet anywhere on Earth. In fact, the astronauts of the Apollo program trained there for their work on the surface of the Moon. And an experiment is currently under way near the summit of Mauna Loa, Mauna Kea’s sister mountain, simulating humans living on Mars.
And the observatories on Mauna Kea are links to other planets as well. For example, significant time at the NASA Infrared Telescope Facility (IRTF) is devoted to studying planets in our solar system, and the W. M. Keck Observatory, shown in the first picture on this page, has been used to discover many exoplanets.