Gaze into the Heavens

My Visit to the ALMA Radio Telescope Array, Northern Chile

During our summer trip, my dad and I visited the ALMA radio telescope array, which is located in Chile’s Atacama Desert. “ALMA” is an abbreviation for “Atacama Large Millimeter Array” and is an astronomical interferometer of radio telescopes that is located in the Andes at an elevation of 16,500 feet above sea level. The array consists of 66 massive radio telescope antennas ranging from 7 to 12 meters in diameter.  The ALMA website describes the Array Operations Site (“AOS”), which is located adjacent to the array, as “the second highest building in the world.”

Apparently, ours was the first tourist group to receive clearance to visit the ALMA array and AOS. We have since been told that we’ll also be the last tourist group that’ll be allowed to visit there, because of health concerns stemming from the high elevation.  Prior to being allowed to visit the main array at 16,500 feet, everyone in our tour group was examined by health care personnel at the ALMA Operations Support Facility (“OSF”), which is a base facility located at around 9,500 feet to assess whether we could safely ascend another 7,000 feet to the array. A doctor took both my systolic and diastolic blood pressures at the OSF medical facility. Once they took my blood pressure, which was in the low 60s, I received clearance to continue on to the array. Unfortunately, not all the tourists in our group received clearance, because of their elevated blood pressure readings.  Overall, the process was nerve-racking, as it took about an hour for our group of 15 people to fill out the required waiver forms, watch a training video, and receive medical examinations.

 By the time we drove the 13 miles and 7,000 vertical feet from the OSF to the array, we had already spent two hours on ALMA Observatory property. Once we arrived at the array, medical personnel at the AOS took our blood pressure again to ensure that we were not experiencing altitude sickness or any other medical problems. One young woman in our group began to feel extremely sick, and she was given an oxygen tank. I also began to feel slightly nauseous, probably because I felt anxious about spending an hour at such a high altitude. However, my diastolic blood pressure was fine and read to be in the 70s. Our group toured AOS, and then we were allowed to go outside and walk around the bases of the nearest antennas in the array.  At one point, many of the giant antennas rotated in tandem as they moved from one target in the sky to another.  It was surprising how little noise they made as they moved.  Here are some pictures we took during our ALMA visit:

Me at the ALMA array, elevation 16,500 feet, with a standard-issue supplemental oxygen canister in hand.



Shortly after this photo was taken, dozens of the giant antennas quietly rotated in synch. Very cool.


Below, I have also attached a link to the ALMA array website, for those who are interested in learning more:

[Link to ALMA website]

It was a surreal experience to be one of the few groups of tourists to ever tour this amazing array of giant radio telescopes.

Next: Continue to Paranal and Cerro Tololo Visits