By Wilson da Silva
MAUNA KEA, Hawaii - The air at the top of this massive dormant volcano is so thin that astronomers can stay only a few days before headaches and blurred vision force them to return to sea level.
“The altitude makes a difference. You definitely think more slowly,” said Dr Richard Jameson, an astronomer from Britain’s Leicester University who was observing a star cluster using an infra-red telescope in one of six observatories on Mauna Kea.
“I reckon it’s like working with a couple of pints (of beer) in you. The altitude doesn’t give you the same euphoric feeling but you’re still a little fuddled,” he said.
The top of Mauna Kea, 13,796 feet (4,203 metres) above the Pacific, is the world’s highest astronomical facility, where five countries will have invested 700 million dollars by the end of the decade.
The skies are clear for 320 days a year and on a moonless night the stars cast a shadow of your hand.
“It’s by far the best-placed astronomical facility in the world,” said astronomer Kevin Krisciunas of the Joint Astronomy Centre, which operates two of the peak’s telescopes and is funded by Britain, Canada and the Netherlands.
The volcano’s peak usually stands 800 feet (243 metres) above the clouds during the day and 5,000 feet (1,524 metres) above them at night.
At this height sunsets are a stirring sight. Traces of volcanic ash from the Philippine’s Mount Pinatubo eruption still permeate the upper atmosphere, adding deep red hues.
Some types of astronomy can be done only from Mauna Kea or in outer space.
With almost half of the image-distorting atmosphere below Mauna Kea’s peak, infrared light can be captured by optical instruments and faint sub-millimetre wavebands received by radio telescopes, which piece together detailed images of the cosmos using the radio signals from space.
The peak is also the site of the world’s most revolutionary optical observatory. The 100 million dollar W.M. Keck telescope, the world’s largest and most expensive, uses new and unique technology.
Unlike most telescopes, Keck’s huge primary mirror is a mosaic of 36 hectagonal reflectors controlled to the last 10-millionth of a metre by a bank of computers. Funded by the private U.S. Keck Foundation, it is due to be completed early near year.
The computers monitor the mirrors continuously and are capable of making 100 alterations a minute to ensure absolute viewing clarity.
“Each mirror costs nearly a million dollars...so we’re careful to tie tools to our hands when we’re working above them,” said lead technician Bob Moskitis.
Mauna Kea’s remoteness kept astronomers away until the first large telescope was built in 1969. Today, it is the site of six observatories with nine telescopes employing 160 people and costing 13 million dollars a year.
In addition to Keck, there are telescopes belonging to the University of Hawaii, the California Institute of Technology, the U.S. National Aeronautics and Space Administration (NASA), Britain, Canada, the Netherlands and France.
Japan will soon join the growing domed city above the clouds with its National Large Telescope, to be built at a cost of 350 million dollars.
This will be followed by a second Keck costing 70 million dollars and an American-British 310-inch (787cm) telescope worth 85 million dollars.
Astronomers chat and listen to compact discs while they watch flickering screens, occasionally becoming agitated when the unexpected occurs for fear it will ruin their meticulously planned and expensive observations.
“You’re a little more punchy at this height, so it pays to get a lot of planning done at sea level,” said Dr Ned Ladd, an astronomer at the University of Hawaii, observing at the James Clerk Maxwell telescope.
After a night on the mountain, astronomers drive down to the 9,000 feet (2,743 metre) level where there are offices, sleeping quarters and a large restaurant serving breakfast at all hours.
“If you’ve had a bad night’s observing, you talk about how trashy the weather was, the thunderstorms,” said Ladd.
“If you’ve had a good night, you want to brag. If it’s a mediocre night that yielded nothing, you just want to go to bed and not talk to anyone.”