Moondark for May: Not In My Backyard
Aloha. There’s no mistaking this for my backyard observatory. We’re 4900 miles to the west, almost 20 degrees latitude to the south and 14,000 feet up. Atop the tallest mountain on the planet (as measured from its base on the ocean floor) and above 40% of the atmosphere sit the observatories on Mauna Kea, the White Mountain.

While the location couldn’t be farther removed from any amateur’s, that’s not all that’s different. Inside the domes, the telescopes themselves are unmatched in size and imaging technology. The main mirrors of the twin Keck telescopes are each 10 meters across--that's 33 feet. Composed of 36 hexagonal segments, computers control their paraboloid shape accurately enough to act as a single primary mirror. Two 8-meter telescopes stand nearby. The Subaru Japan National Large Telescope is adjacent to the Kecks. The Gemini North Telescope lies closer to the mountain's true summit. Even its enclosure is high-tech, engineered with wind vents around the dome that open to equalize temperatures and minimize turbulence. Within the dome, the 8-m monolithic thin mirror is flexible enough that actuators control the shape perfectly regardless of where it is pointed in the sky. Note that here on Mauna Kea, the 3.6-m primary of the Canada-France-Hawaii Telescope is considered "mid-sized."

Imaging technology at Mauna Kea is out of this world too. Equipped with adaptive optics to take advantage of the naturally superb seeing on the mountain, the "big glass" and turbulence-canceling optics permit resolution almost as good as from space-based telescopes at certain wavelengths. What you can’t see buried along the steep, rugged summit road is the fiber optic internet links that wire the summit to the headquarters and the rest of the world. While there are nighttime technicians on site, the telescopes are most often used remotely at the headquarters in the Waimea and Hilo far below.

A trip to the top is an sureal experience, an adventure from steamy tropical beaches to lifeless snow-covered lavascapes. The air is thin, but the force of the wind is unyeilding. This is a sacred place to the native Hawaiians, and home to the snow goddess, Poli'ahu. Not all are comfortable with the extensive development of the site for astronomy (two dozen telescopes at present), and there are concerns that visitors and construction have disturbed hidden graves and heiaus (altars) (Sky and Telescope, August 2001, p. 40).

Mauna Kea is widely regarded as the best observing site on the planet. Where else would you put a billion dollars worth of telescopes? You can’t argue with a location so far above the weather and virtually all humidity that sports more than 320 clear nights a year. The minimal light pollution from Kona and Hilo is usually blanketed by a cloud layer. Amateurs are welcome to enjoy the Mauna Kea skies at the Onizuka Visitors Center at a mere 9,200-foot elevation. (See Jay Reynolds Freeman‘s article in the June 2002 Sky and Telescope, p. 100.) Just bring your own scope and remember to pack your parka. Mahalo.

Doug and Maureen enjoyed sunset atop the world with Mauna Kea Summit Adventures. Unable to travel? Take the aerial tour of the observatories. Moondark is written by Doug Miller, published on the web, and printed in the Delmarva Star Gazers' Star Gazer News. Please address comments and suggestions to dcmiller@dmv.com. This document was last revised on 28 April 2002. All text and images copyright © 2002 Douglas C. Miller, All Rights Reserved. This material may not be reproduced in any form without prior permission.