Iconic Arecibo telescope goes silent after major damage

Early Monday morning, a cable suspended above the Arecibo telescope in Puerto Rico snapped and left a 100-foot-long gash in the dish of the iconic radio telescope. The 3-inch-diameter cable also damaged the panels of the Gregorian Dome which hangs hundreds of feet above the antenna and houses the telescope’s receivers. It is not known what caused the cable break or when radio astronomers using the telescope will be able to resume their research.

“This was an auxiliary cable used to support the weight of the platform, and we are in the process of evaluating why it broke,” says Zenaida Kotala, assistant vice president for strategic initiatives at the University of Central Florida, which operates the observatory. . “We are working with engineers to define a repair strategy. Our aim is to get the facility operational as soon as it is possible to do so safely. “

Astronomers have used the Arecibo radio telescope to study the cosmos since 1963. For most of its life, the observatory was by far the largest telescope of its kind in the world. (It was only recently overtaken by China’s FAST radio telescope.) Its 1,000-foot radio antenna is embedded in a natural depression in the surrounding hills and acts like a giant ear listening to weak radio signals from distant galaxies, very distant.

“Being bigger is just more sensitive,” says Seth Shostak, senior astronomer at the nonprofit SETI, a leading research institution in the search for extraterrestrial intelligence. “Just as a larger optical telescope can see fainter objects, a larger radio telescope can also ‘see’ paler things.

The Arecibo radio telescope has been used for a wide range of scientific experiments and has been at the center of a number of firsts that have changed our understanding of the universe. In 1994, astronomers studying a pulsar with Arecibo found the first evidence of a planet orbiting another star. Arecibo also detected the first millisecond pulsar, a type of rapidly rotating star that is used as an astrophysical clock in the hunt for gravitational waves, and the first repeat Fast Radio Burst, a brief pulse of high-energy radiation that scientists begin only to understand.

The history of the Arecibo telescope is also deeply linked to the history of SETI. Planetary astronomer Frank Drake, who conducted the first SETI radio research the same year construction on Arecibo began, was the director of the observatory for years. In 1974, he and Carl Sagan used the telescope to transmit the world’s first interstellar message to a star system 12,000 light years away. It was a short pictorial message depicting humans, our DNA, and even the Arecibo dish itself. Since then, Arecibo’s SETI activities have mainly focused on listening to ETs. (Although in 2009, artist Joe Davis did plug his iPhone into the antenna and use it to transmit a second interstellar message.)

“A unique asset in SETI”

“We were extremely saddened by the news from Arecibo,” says Andrew Siemion, director of the Berkeley SETI Research Center. “Arecibo is a unique asset in SETI and we look forward to its return to science operations.” For years, Siemion and his colleagues at Berkeley collected Arecibo radio data for SETI @ Home, a distributed computing project that enabled anyone with an internet connection to help find intelligent aliens. . Earlier this year, the SETI @ Home project stopped collecting new data from Arecibo and other radio telescopes so that its researchers could focus on analyzing the data already collected.

Arecibo also taught scientists a lot about our own solar system. When not listening to aliens or pulsars, the radio observatory can be used as a planetary radar. It generates a powerful beam of radio energy and bounces it off an object of interest in our solar system, such as a planet or an asteroid. “Its ability to send and receive radar signals makes it extremely valuable to the planetary scientific community,” says Bruce Betts, chief scientist of the nonprofit Planetary Society. By studying the radio reflections from these objects, planetary scientists can gain detailed information about their orbits, map their surfaces, or study their composition. In fact, the telescope plays a crucial role in NASA’s planetary defense program, which is tasked with detecting and mitigating threats from giant killer asteroids.

But all these scientific operations will have to be put on hold until the Arecibo antenna is repaired. While this is the most damage done to the observatory in recent memory, it is not the first time the telescope has been hit. In 2014, an earthquake damaged an observatory cable and Hurricane Maria hit the telescope a few years later. But Ramon Lugo, director of the Florida Space Institute at the University of Central Florida, says the previous damage to the Arecibo telescope doesn’t really compare to what happened this week with the broken cable. “Nothing like this has ever happened before,” Lugo says.

Money problems

The damage inflicted on Arecibo by Hurricane Maria came at a particularly inopportune time for the observatory, which then faced serious funding problems. Arecibo is mainly supported by grants from the National Science Foundation, which provided the observatory with $ 12.3 million in emergency funds for hurricane-related repairs in 2018. Kotala says it’s still unclear how much it will cost to repair the damage caused by the broken cable, but she is confident that the observatory will get the funding it needs.

“We have had many challenges since we started operating and managing the observatory, but the team and our local community have been resilient and continue to move forward,” says Kotala. “We have the full support of the NSF and our NASA stakeholders to make the necessary repairs to return to full operational capability. It’s another chance to show the world that this team can weather the storm. “

This story first appeared on wired.com.