After the Sun sets over the Atacama Desert’s Valley of the Moon,
the 19,400-foot volcano Licancabur catches the last rays of sunlight.
Richard Talcott
I recently returned from a 9-day trip to Chile — one of more than 30 participants in a tour sponsored by Astronomy magazine and organized by MWT Associates. We all had a great time, despite long plane rides from the States down to Santiago. Our two main reasons for going were to experience the clear skies of the Atacama Desert and the giant telescopes at Cerro Tololo Interamerican Observatory, but plenty of other sites kept us busy. Last week I wrote about the majestic southern skies and the El Tatio geysers. This week we explore the Valley of the Moon.
Thursday, August 16, dawned as the previous days had: bright, sunny skies and comfortable temperatures. Our morning was free to check out the marketplace in San Pedro de Atacama, and many of us took advantage. Pesos flew out of our wallets thousands at a time (not to worry — the exchange rate was about 500 pesos to the dollar), but the shopkeepers kept up with our seemingly insatiable desire for local wares and souvenirs.
Late in the afternoon, we climbed aboard our motorcoach for the next scenic destination: the aptly named Valley of the Moon. Apparently, early explorers thought the valley looked like what they envisioned the Moon to be. They weren't all that far off. The striking landscape owes its beauty to eons of wind erosion transforming the salt-rich mountains.
But the main reason people visit the Valley of the Moon is to watch the Sun set over the valley and on the Andes Mountains. The bus let us off at the base of a massive sand dune, which we climbed to get the best views. Once at the top, some of us hiked even farther to get different perspectives.
It was all worth it. The constantly changing colors on the distant Andes took our breath away as effectively as the hike at 7,000 feet to get there. The high mountains held the sunlight for quite a while, although not as long as you might think: The Atacama's low latitude (it straddles the Tropic of Capricorn) means twilight doesn't last as long as it does at mid-latitudes.
After sunset, we headed to a gorgeous spot just outside the valley for dinner under the stars. We then had more time to get acquainted with the southern night sky. The area was so dark that the crescent Moon cast noticeable shadows. Our low latitude then provided another unexpected treat. As the Moon set, the cusps of its crescent stood perpendicular to the horizon so, for a few minutes after the bulk of the Moon had disappeared, we still could see the two lit cusps.
After moonset, the sky grew dark enough for more serious observing. Yet after a while, we noticed we could see the ground clearly enough to walk around even without using a red flashlight. The Milky Way was casting enough light to see by — another pleasant surprise in a week chock full of them.
Next up: Cerro Tololo Interamerican Observatory.