Saturday, March 24, 2001

Sunset

Officially, there is only one sunset a year at the South Pole, coinciding with the Autumnal Equinox, the beginning of fall in the Southern Hemisphere. The astronomers here did a few calculations and decided the Sun would finally dip over the horizon and out of sight at about 4 A.M. South Pole time last Friday, March 23. So on Thursday night, we had the traditional sunset party to say farewell to our faithful friend for the last five months. Usually this event is held in the Skylab Lounge, but this year we chose a new venue that was much more spacious and had even more windows: The New Station.

I have been watching the progress of the station’s construction all summer, but the party was actually my first time inside the giant elevated structure. The windows on the building always seemed tiny from the ground below where I take my weather observations, but from the inside I could see they are huge. They would have afforded excellent views of the sunset too, if it hadn’t been cloudy.

There was not a cloud in the sky the week before, but now it was overcast and foggy. Eventually, the fog cleared enough for the horizon to be discerned, but clouds continued to hinder our view of the Sun.

Despite the disappointing weather, most Poleys showed up and it was a great opportunity to tour the module that is soon to be the new center of life the South Pole. The walls are not in yet and the two vast rooms that are the first and second floors are dark and yawning, but with a few couches and lights in the corner of the second floor, we brought the place to life in the area where the new Galley is to be constructed next year. Sitting around eating cheese and crackers with wine of a curious consistency that had been accidentally frozen and re-thawed, we talked and waited for the Sun to make an appearance. It never did.

I was awakened the next evening by a phone call. Meghan told me the weather had cleared and there were people in the Skylab Lounge watching the sunset. I hurried out of bed and run up the stairs to the lounge.

Sure enough it was clear along the horizon, and the final melting of the Sun over the Polar Plateau was visible. It was like a fire in the distance, burning bright orange, occasionally flashing brilliant greens and blues. The lounge’s resident reflecting telescope offered an even more spectacular view of the amazing sunset.

The longest sunsets anywhere in the world are at the Earth’s Poles. They are caused not by the revolving of the Earth on its axis, but by the slow revolution of the Earth around the Sun into a place where the Pole is in continuos shadow. Behind a veil of clouds, our sunset had been going on for days. Luckily, it was clear enough to see the best part: after it actually sets. Even as we watched the very top of the Sun slowly burn along the landscape, the whole Sun was really already below the horizon. Like a lens, the extreme cold air here can refract light considerably, and makes it possible to see the Sun when it isn’t really in one’s line of sight. As the dynamics of the atmosphere continuously move warm air and cold air above and below each other, the very top of the Sun can actually appear to rise and set several times.

What an amazing sight it was! Seeing the Sun slowly set and flash, then disappear, only to return several minutes later. Sometimes it would be gone for a while, and revisit higher and brighter than before. We sat up in the lounge for hours watching this cycle. It almost seemed like time was playing tricks, moving backward and pausing. In most places, a sunset is over in minutes, and one might be lucky enough to see an elusive ‘green flash’ for a fraction of a second during the final descent. A sunset is a moment you wish you could freeze in time, hold it there and feel all the power and splendor of its grandeur. It was incredible to be in a place where I could do just that, to be able to hold onto that beautiful instant, and watch the Sun sit on the edge of the world as time stands still.