If measured from the sea floor, you are 13,808ft in the air, on top of, technically, the tallest mountain in the world. Massive observatories rise around you, shining silver on the stark terrain, like a human colony on an alien planet. These observatories comprise the greatest collection of telescopes on earth; the summit is above 40% of the earth's atmosphere and 90% of its water vapor, resulting in many cloudless nights. Be sure to bring long pants, a thick coat (or lots of layers), a warm hat and gloves. It gets cold up here.
It's a veritable UN on the mountaintop, with a bevy of countries administering different telescopes – Taiwan and the USA collaborate on the Submillimeter Array ; the UK and Canada run the James Clerk Maxwell Telescope (JCMT) ; and six nations share the Gemini Northern 8m Telescope . The University of Hawaiʻi 0.9m Telescope is now used mostly for training undergraduates. Most of these observatories are closed to the public, and none allow public viewing through their telescopes.
Sunsets are phenomenal from around the summit. All of Hawaiʻi lies below as the sun sinks into an ocean of clouds – while the telescopes silently unshutter and turn their unblinking eyes to the heavens. Look east to see 'the shadow' – the gigantic silhouette of Mauna Kea looming over Hilo. Moonrises can be equally as impressive: the high altitude may make the moon appear squashed and misshapen, or sometimes resemble a brushfire.
If you have a 4WD, you may drive to the summit in the daytime, but you must descend 30 minutes after sunset. It takes about half an hour to drive the 8-mile summit road, the first 4.5 miles of which are slippery gravel. Just before the pavement picks up again, the area on the east side of the road is dubbed Moon Valley , where Apollo astronauts rehearsed with their lunar rover before their journey to the real moonscape.
