Watching the Stars at San Pedro Mártir

Mexico's National Astronomical Observatory (Observatorio Astronómico Nacional (OAN)) nestles high in Sierra de San Pedro Mártir, Baja California. Three large telescopes scan the stars, feeding back vital information. Scientists, researchers and the occasional interested tourist book their times to view the solar system.

The dark skies above are protected, in law, from light pollution. The high altitude, low humidity, little radio wave interference and low atmospheric pollution render this the perfect place from which to stare at the wonders of our universe.

The OAN moved several times, before finding its present home. It was officially opened on May 5th, 1878, from its base in Chapultepec Castle, Mexico City. Back then, there was a fixed telescope, 18ft (5.5 meters) in length, and an Ertel's meridian circle. The launch event saw observers using these telescopes to focus upon two stars in the constellation, Bootes.



Over the following century, the telescopes were dismantled and relocated further and further out into the Mexican countryside. Mexico City's growth had led to too much light pollution for the OAN to be usefully based there. The telescopes were updated, as technology moved on.

In 1967, it finally found its permanent headquarters, in the mountains of San Pedro Mártir. Brand new telescopes were built to serve its expanding needs and to secure its place in the advancement of science. The astronomical community have been making the pilgrimage ever since!



However, its general remoteness can make basic facilities a little challenging.

The same things which make this observatory an incredible place to stargaze also make it a fun challenge for Baja adventurers to reach. Although scientists and locals work hard to maintain it, the dirt road which leads to it from the Transpeninsular Highway can be difficult to traverse - especially in winter due to snow and rain. Four wheel drive vehicles are highly recommended. Travelers and campers are also strongly encouraged to bring their own food, gasoline, water and car repair tools. The OAN provides shelter only to their professional visitors; others must fend for themselves, largely because the OAN generates their own electricity at the observatory site, hauls in their fuel from Ensenada and pumps all water from a well 5 miles away from living quarters. They have very little to spare!
Sierra San Pedro de Mártir Observatory

The observatory is part of the Institute of Astronomy. For those wishing to adventure up there, then there are travel tips given, in English, on this site.