Mauna Kea–lit. “White Mountain”–stands 4205 meters (13,976 feet) above the ocean surface and nearly 9144 meters (30,000 feet) above the ocean floor, making it the tallest mountain in the world.
The weather patterns surrounding Mauna Kea created by its close proximity to the Pacific ocean and Mauna Loa, and the trade winds establish an inversion layer. This inversion layer traps a thin line of clouds between the base of the mountain and its summit. With so much moisture drawn away from the summit–an hardly any light sources around–Mauna Kea is one of the best star gazing venues in the world.
Several premier observatories have capitalized on this fact, as have many local tour companies who offer guided trips to the visitor’s center to show off more of the milky way than most people are used to seeing.
This post-shield volcano was most recently active between about 6,000 and 4,000 years ago with at least seven separate vents erupting. Overall, the mountain is judged to be about 1 million years old.