Early morning steam rises from numerous geysers and fumaroles
at El Tatio — the world’s highest-altitude geyser field. Evelyn Talcott
I've just 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.
When we arrived in Santiago Sunday morning, August 12, the skies were far from perfect. Winter isn't the clearest season in central Chile, and the day greeted us with occasional light showers and drizzle. Not the best conditions for our city tour, but we saw the major sites, including the presidential palace where Salvador Allende died during the 1973 coup.
On Monday morning we flew to Calama and then took a bus to San Pedro de Atacama, a town of 5,000 human inhabitants and seemingly as many dogs. The partly cloudy skies of the first day didn't match our weather expectations. Because parts of the Atacama haven't received rain in recorded human history, we didn't expect to see any clouds. Our first night's observing by the hotel proved less-than-stellar, with spotty clouds marring the view of the southern-sky delights we all eagerly sought.
Fortunately, the weather turned beautiful the next day. (We later learned it had been cloudy for much of the previous week, so our timing was impeccable.) We took a tour of the town and its archaeological museum, but our main focus was on the sky that awaited us after sunset.
We weren't disappointed. That evening, we saw the central regions of the Milky Way in Scorpius and Sagittarius directly overhead. South from there, we had great views of Centaurus and its magnificent globular cluster, Omega Centauri. Closer to the horizon, Crux and Carina dominated the view. We even got a good look at the Small Magellanic Cloud, one of two bright satellite galaxies of the Milky Way visible from the Southern Hemisphere.
The next morning, an early wake-up call got us moving toward the world's highest geyser field — El Tatio — near Chile's border with Bolivia. On the way, we pulled the bus over to get a view of the pristine morning sky. By then, the wondrous Large Magellanic Cloud had joined its smaller sibling. One observation of particular interest to me was the zodiacal light, plainly visible in the east before dawn just as it had been the previous evening in the west after dusk. It was the first time I had seen the light twice in the same day.
After climbing on a bumpy dirt road over the aptly named "Devil's Slope," we arrived at the 14,000-foot-high geyser field as dawn was breaking. The geysers and fumaroles appear best at dawn as sunlight illuminates the steam they produce and the relatively high relative humidity keeps the steam from dissipating immediately. As the humidity drops toward 0% later in the morning, the steam nearly disappears.
Despite the dry, high-altitude, and no-doubt harsh environment of the Andes Mountains, we saw several intriguing species as we made our way back to San Pedro. Several herds of vicuña posed for us, and we even got a good view of the rare and shy bird known as a rhea. On the trip back to town, we stopped at a hot springs for a quick soak and a late lunch — the perfect way to wrap up a glorious day.
Next up: sunset at the Valley of the Moon.