Arecibo Observatory

Who would imagine that the biggest telescope in the world is located in the middle of nowhere?  The drive up was quite a haul.  There were winding roads and stray animals all around.  Arecibo is a huge reflector telescope that is located in Puerto Rico.  We visited the Arecibo Observatory and learned a lot about its history, its construction, and how it’s used.

Panoramic photo of Arecibo Observatory.

Arecibo was very precisely placed and there are many factors that led people to construct Arecibo where it is now.  Arecibo was being built by the NSF, NASA, Cornell University, and United States Department of Defense, therefore had to be on U.S soil.  It was going to be constructed on the equator but, they soon found out that they would only be able to see one section of the sky. Puerto Rico is situated 18.5 degrees north, so the astronomers can see a larger portion of the sky.  When they chose Puerto Rico, they found that there was a natural sinkhole that would allow them to construct the reflector more efficiently.

Arecibo was the largest radio space telescope in the world, with a diameter or 305m from its completion in 1963 until a new and more improved telescope was built in China in July of 2016. The reflector is made out of nearly 40,000 perforated aluminum panels. The engineers chose perforated panels because they can drain water if it rains, and they reflect the radio signals better.  If there trees or debris on the reflector, it can mess up their signal.  So, engineers designed special shoes that distribute your weight so that you can walk across the reflector, pick up the debris, and not damage it.  To hold up the sensing equipment that is housed in the Gregorian Dome, they use thirty-six cables each weighing eleven tons.  Those cables suspend the equipment 450 feet above the reflector.

Sensing equipment suspended above the reflector.  The ball on the left is the Gregorian Dome.

The reflector dish that focuses the radio waves to the antenna.  The black stuff on the panels is mold that has accumulated over time.  The mold does not interfere with any signals that Arecibo receives.

Many very important discoveries have been uncovered at Arecibo.  After the construction was finished scientists from all over the world started to pour in, to study all of the data collected at Arecibo.  One of the first things that they explored was the rotation period of Mercury.  They discovered that instead of the estimated 88 day rotation, it was actually only 59 days!  They also got the first image of an asteroid, and they continue to improve on that and track all asteroids that might collide with the Earth.  The main part of space that they conduct research on is the ionosphere, which is an atmospheric layer of space that is located 50 to 600 miles above the Earth’s surface.  So far two movies have been filmed at Arecibo, a James Bond movie and Contact. When they were filming the James Bond movie they found out that the actor was scared of heights, so a stunt double did all of the work.

Arecibo is an amazing observatory that accomplishes a lot of scientific research.  It was a huge accomplishment for engineers, and has led to many amazing discoveries.  If you’re visiting Puerto Rico you should stop down for a few hours in the afternoon and enjoy learning about the telescope!

References:

http://www.space.com/33357-china-largest-radio-telescope-alien-life.html

http://websites.suagm.edu/ao/

http://websites.suagm.edu/ao/radiotelescope_details

https://en.wikipedia.org/wiki/Ionosphere