In the dark, the visitors could see the red glow of molten lava flowing from the volcano Kilauea some 30 miles away, toward the southern end of the island. Before starting their 16-hour observing session, the astronomers spent the previous night getting a bit acclimated to the thin air at a base camp at the 9,000 foot level and working out bugs in the computer software and communications. Instead, they said, they felt compelled to make the periodic trek to this forbidding summit, where the wind chill on this night sank to minus 4 degrees Fahrenheit, in gusts up to 45 mph, at the same time the beaches a couple of hours away were enjoying balmy subtropical temperatures. The atmosphere here has just 60 percent of the oxygen and 10 percent of the moisture found at sea level. The pressure is so low that vacuum-sealed potato chip bags here puff up to the bursting point, hinting at the effects on the human body.
Human vision is dimmed, so that the stars seem duller and fewer in number even than usual.
But for telescope seeing, the place is almost perfect. It is a sophisticated prism the size of a living room, weighing eight tons, with a series of lenses and mirrors that break the light into thousands of wavelengths, or colors, from red to blue. It is the biggest and most precise spectrograph in the world, Marcy said. His sherpa guide was Vogt, his former teacher, spectral guru and the newest member of his team. Vogt directed the construction of the giant new spectrograph.