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Image: The author (on crutches) visiting the Atacama Large Millimeter/submillimeter array high site at over 16,000 feet.
Nine astronomy educators were chosen to visit Chile this June for ten days as part of the National Science Foundation-funded Astronomy in Chile Educator Ambassador Program (ACEAP). They were sent to experience why Chile is one of the astronomy capitals of the world and I was lucky enough to be one of those educators.
I have never been south of the equator and I was amazed to see a sky unfamiliar to me. As the director of MSU’s Abrams Planetarium, I teach primarily about Northern Hemisphere sky. But astronomy is necessarily a global effort and I saw firsthand why Chile is frequently chosen as a partner.
Your latitude determines what parts of the sky you can observe. For most places on Earth, there will always be a fraction you can never see. As a result, it is necessary to have telescopes at multiple latitudes. There are number of locations in the Southern Hemisphere that can and do host observatories, but Chile remains a frequent choice for several reasons.
Importantly, Chile has high desert mountain peaks that limit the atmosphere the telescope must look through. Atmosphere allows us to breathe, traps the sun’s warmth, and blocks dangers from space. However, that same atmosphere is vexing for astronomers. It results in twinkling stars, which blurs images. Water molecules also absorb some wavelengths of light astronomer’s wish to observe. So, the higher and drier the location, the better.
Due to these near ideal observing condition along with Chile’s welcoming attitude toward astronomers, the country is home to over 40% of the world's astronomy infrastructure and that number is expected to reach 70% in the next seven years. In our short visit, we went to four of these observatories.
Our first stop was Gemini South, an 8-meter diameter telescope that has a twin in Hawaii and sits on the peak Cerro Pachón. Gemini uses a technology known as adaptive optics, a system that uses a laser reflected off our atmosphere to measure the distortions caused by moving air. Using sensitive actuators, it deforms a mirror just right to cancel out those distortions. This allows Gemini South to take images that rival the resolution of the Hubble Space Telescope at times.
Down the road from Gemini is the SOuthern Astrophysical Research Observatory, or SOAR. This was an amazing treat for me as MSU is a major partner. Astronomers at MSU have guaranteed time to use it each month. MSU Professors Jay Strader and Laura Chomiuk use it to look for black holes in ancient globular clusters. Professor Megan Donahue and her student Tom Connor use SOAR to study how active galaxies turn on and off and are finding answers not predicted by theory.
These projects require a lot of time on telescopes that is difficult to get at other observatories. But our partnership allows them to monitor their targets and find unexpected results. MSU has set up a remote console to control SOAR on the first floor of the Biomedical and Physical Sciences Building on MSU’s main campus in East Lansing. You can visit and peak inside the windows whenever the building is open.
We also visited the Cerro Tololo Inter-American Observatory, which houses the 4-meter Blanco Telescope. This telescope was used in the 1990s by two teams of astronomers to study supernovae in distant galaxies. The goal was to understand how the universe was expanding, with the expectation of finding evidence that it was decelerating. Instead, the observations shocked the astronomy community and showed the universe was accelerating in its expansion. Both teams jointly won the 2011 Nobel Prize in physics for this discovery.
Photo below: The Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile at sunset, June 25th 2015. Article continues after image.
Finally, we visited the Atacama Large Millimeter-Submillimeter Array, or ALMA. This observatory is a set of 66 radio antennas that act as a telescope miles in diameter. It is located on the Chajnantor Plateau at an elevation of about 16,500 feet. The air is so thin that we had to be cleared by medical staff and carry oxygen canisters to visit. Our time was limited to less than 2 hours to avoid adverse health effects.
The extreme conditions where ALMA sits and its configuration have allowed it to take stunning images of objects in detail never seen before, such as its ground-breaking images of HL Tau, a new forming solar system where we saw for the first time predicted gaps in a surrounding disk from newly forming planets.
Chile houses some of the world’s most powerful ground-based telescopes that have resulted in brand new discoveries. I hope to bring new programming about astronomy in Chile to our planetarium over the next couple of years. I also expect to give several talks over the upcoming months about my trip. You can find out when those talks will happen on the Abrams Facebook page or check my blog (astroshanno.wordpress.com) for announcements.
Shannon Schmoll, PhD, is the Director of the Abrams Planetarium.
Below: The members of the Astronomy in Chile Educator Ambassador Program in front of the 8-meter Gemini South telescope. Photo by Peter Detterline.
This article was originally published at ELi last Wednesday.
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