The 13,796-foot summit of Mauna Kea, the world’s tallest mountain if measured from its base on the ocean floor, is one of the best places on earth for astronomical observations, thanks to its location in the tropics, pollution-free skies, and pitch-black nights. It’s home to the world’s largest telescopes—and more are planned, to the dismay of some Native Hawaiians—but the stargazing is fantastic even with the naked eye.
The Onizuka Center for International Astronomy, as the visitor center is formally known, lies about an hour from Hilo or Waimea, 6.25 miles up Summit Road and at 9,200 feet of elevation, above which people may start to feel light-headed. Named for Big Island native Ellison Onizuka, a victim of the 1986 Challenger explosion, it’s open daily from 9am to 10pm (with 24-hr. restrooms), offering displays, interactive exhibits, and a bookstore with food and drink for sale, including hot items to take the chill off.
You can do also some serious stargazing from 6 to 10pm, for free. The program begins inside with a screening of “First Light,” a documentary about the cultural and astronomical significance of Mauna Kea, and then offers visitors a chance to peer through telescopes at planets and other celestial phenomena, with a guide highlighting where to look. Feel free to bring your own telescope or binoculars, along with a flashlight (with a red filter, to avoid glare).