This is a great dish! The Arecibo radio telescope in its salad days.
Early Monday morning, a cable suspended over the Arecibo Telescope in Puerto Rico broke, leaving a 100-foot cut in the shell of the legendary radio telescope. The 3-inch diameter cable also caused damage to the panels of the Gregorian dome, which hangs several hundred meters above the shell and houses the telescope's receivers. It's unclear why the cable tore or when radio astronomers using the telescope will be able to resume their research.
"This was an auxiliary cable that was used to support the weight of the platform, and we are currently investigating why it broke," said Zenaida Kotala, vice president of strategic initiatives at the University of Central Florida, which manages the observatory. “We work with engineers to define a strategy for repairs. Our goal is to get the system ready for operation as quickly as possible. "
Astronomers have been studying the cosmos with the Arecibo radio telescope 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 surpassed by China's FAST radio telescope.) Its 1,000-foot radio dish is built into a natural indentation in the surrounding hills and acts like a giant ear listening to weak radio signals from galaxies far away.
"Because it's bigger, it's just more sensitive," says Seth Shostak, senior astronomer at the nonprofit SETI Institute, a leading research institution in the search for extraterrestrial intelligence. "Just as a larger optical telescope can see weaker objects, a larger radio telescope can" see "weaker things."
The Arecibo radio telescope has been used for a variety of scientific experiments and has been the focus of a number of innovations that have changed our understanding of the universe. In 1994, astronomers using Arecibo to study a pulsar found the first evidence that a planet is orbiting another star. Arecibo also discovered the first millisecond pulsar, a type of rapidly rotating star used as an astrophysical clock when searching for gravitational waves, and the first repeated fast radio burst, a short pulse of high-energy radiation that scientists are only just beginning to understand.
The history of the Arecibo telescope is also deeply woven into the history of SETI. Planetary astronomer Frank Drake, who carried out the first radio SETI search the same year construction of Arecibo began, was director of the observatory for years. In 1974, he and Carl Sagan used the telescope to send the world's first interstellar message to a star system 12,000 light-years away. It was a short picture message depicting people, our DNA, and even the Arecibo dish itself. Since then, Arecibo's SETI activities have mainly focused on listening to ET. (Though artist Joe Davis effectively put his iPhone in the bowl in 2009, sending a second interstellar message.)
"We were extremely sad to hear the news from Arecibo," said Andrew Siemion, director of the Berkeley SETI Research Center. "Arecibo is a unique asset in SETI and we look forward to returning to scientific operations." For years, Siemion and his colleagues in Berkeley collected radio data from Arecibo for SETI @ Home, a distributed computer project that allowed 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 researchers can focus on analyzing the data already collected.
Arecibo has also taught scientists a lot more about our own solar system. When not waiting for aliens or pulsars, the radio observatory can be used as a planetary radar. It creates a strong beam of radio energy and reflects it off an object of interest to our solar system, such as a planet or an asteroid. "Its ability to transmit and receive radar signals makes it incredibly valuable to the planetary science community," said Bruce Betts, chief scientist for the nonprofit Planetary Society. By studying the radio reflections of these objects, planetary scientists can get 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 posed by giant killer asteroids.
But all of these scientific operations must be halted until Arecibo's court is repaired. While this is the most damage done to the observatory in recent times, it is not the first time the telescope has taken a hit. In 2014, an earthquake damaged a cable at the observatory and Hurricane Maria hit the telescope a few years later. However, Ramon Lugo, the director of the Florida Space Institute at the University of Central Florida, says previous damage to the Arecibo telescope doesn't really compare to what happened to the broken cable this week. "Something like this has never happened before," says Lugo.
The damage caused by Hurricane Maria Arecibo came at a particularly unfavorable time for the observatory, which at that time was fraught with major funding problems. Arecibo is supported primarily by grants from the National Science Foundation, which provided the observatory with $ 12.3 million in emergency funding for hurricane-related repairs in 2018. Kotala says it is still unclear how much it will cost to repair the damage caused by the broken cable, but she is confident the observatory will get the funds it needs.
"We have had numerous challenges since we started operating and managing the Observatory, but the team and our local community have resiliently and continue to make progress," says Kotala. “We have the full support of both NSF and our NASA stakeholders to make the necessary repairs to be fully operational again. This is another opportunity to show the world that this team can weather the storm. "
This story first appeared on wired.com.