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GBT integral part of search for extraterrestrial intelligence

The Green Bank Telescope is the primary instrument in the Breakthrough Listen search for extraterrestrial intelligence. The project is part of Breakthrough Initiatives, founded by Yuri Milner and Stephen Hawking. Photo courtesy of Patrick Samansky, AP
The Green Bank Telescope is the primary instrument in the Breakthrough Listen search for extraterrestrial intelligence. The project is part of Breakthrough Initiatives, founded by Yuri Milner and Stephen Hawking. Photo courtesy of Patrick Samansky, AP

Suzanne Stewart
Staff Writer
As the world’s largest, fully steerable radio telescope, the Green Bank Telescope is a hot commodity. There are things the GBT can do that can’t be done by any other radio telescope in the world.

That is why, when Breakthrough Initiatives board member Yuri Milner, founder of DST Global, needed a radio telescope to be part of the Breakthrough Listen project, he made a call to the Green Bank Observatory.

“Breakthrough Listen is a privately-funded endeavor to look for signals of extraterrestrial intelligence,” GBO director Karen O’Neil said. “Big picture, that’s all it is. When we were approached by Yuri Milner’s group about being part of this, my initial question was, ‘why us? We’re thrilled. We very much want to do this, but out of curiosity, why us?’”

While the GBT does have an impressive résumé, it is not the largest radio telescope in the world. The Arecibo Telescope in Puerto Rico, and the FAST – Five-hundred-meter Aperture Spherical Telescope – in China are both larger than the GBT, but they are unable to study as much of the sky as the GBT.

“The GBT has a much wider range of wavelengths it can look at than Arecibo, and that just gives us a better shot at trying to see what’s out there,” O’Neil said. “The much more important reason is that, although Arecibo is a larger telescope and more sensitive, it’s fixed to the Earth as is the FAST Telescope, and so that means they can only see that sky that passes overhead. The GBT can actually see eighty-five percent of the sky because it can twist and turn and look around. So although Arecibo and FAST might be more sensitive, the GBT’s flexibility makes it a far more worthwhile telescope to use.”

The $100 million funded project is the largest ever scientific research program aimed at finding evidence of civilizations beyond Earth, according to its website,

Breakthrough Listen is utilizing the GBT, the 64-metre diameter Parkes Telescope in Australia and the Automated Planet Finder Telescope at Lick Observatory in California.

The project requires several telescopes to ensure there is no interference in the results.

“The majority of the search is being undertaken with radio and the reason for that is that if you think about civilizations and you think about signals that you can decipher, a radio signal is actually going to be easier to send and decipher than an optical signal. The GBT is the primary instrument for looking at radio signals,” O’Neil said.

“They have a second telescope in Australia, the Parkes Telescope, for two reasons,” she continued. “First off, if you find a signal, you really need a telescope very far away to confirm it to ensure that you are not picking up a local signal, so that you know it’s astronomical. Equally important, the GBT is up in the northern hemisphere and unfortunately for astronomers, the center of the galaxy which is where you have the most stars is actually primarily visible to the southern hemisphere. So the Parkes telescope is able to more readily view the galactic center as well as the southern sky that we can’t see as easily here with the GBT.”

The project will observe and study the 100 nearest stars and all the stars with Kepler planets, which are planets discovered by the Kepler spacecraft. After that, they will target different stars to cover as much of our galaxy as possible, as well as looking at other galaxies, to see what is out there.

What makes the Breakthrough Listen project different from other SETI [Search for Extraterrestrial Intelligence] projects is that it will return again and again to the same area to see if the data is consistent over a period of time.

“If every time you look at a certain star, you see a pattern – you look at it once, you might decide, ‘oh that pattern looks like something human beings made,’ so you blow it off as what we call radio frequency interference, but if, over time, every time we look at this area of the sky and we see that pattern and we’ve never seen that pattern any place else, then you can actually say, ‘I thought it was human, but maybe it’s not. Maybe it’s something we need to look at further.’ So that’s a much more interesting set of data to look at and a much more interesting problem to solve. That’s kind of the big picture.”

As the data is collected and the scientific minds involved are able to share information, O’Neil said she hopes they will give a public talk at the GBO to allow the community to know what has been discovered with use of the GBT.

“We would love that,” she said. “The wonderful thing about Breakthrough Initiatives and the Breakthrough Listen project is that they really picked some of the best scientific and engineering minds in the world to be a part of this and to provide oversight. The problem when you pick the best scientific and engineering minds in the world is, they are people who are very busy with many, many things out there. It is something that we’ve talked about. We would love to see some of these folks coming here.”

Breakthrough Initiatives has signed a 10 year partnership with GBO as part of the Breakthrough Listen project.

O’Neil said the collective is aware of the National Science Foundation’s current plans to create an Environmental Impact Statement for the GBO which may result in mothballing or deconstruction of the facility.

Despite the unknown future of the facility, Breakthrough Initiatives has provided support for the GBO.

“In a way you could already say they’ve helped us in probably the best possible way which is by bringing in not just funding, but funding for the long term,” O’Neil said. “They’re not coming in and saying, ‘hey, we’re going to do this for a year, maybe next year, we’ll decide if we want to.’ They’ve come in and made a ten-year commitment to this facility, which is fantastic.

“In that sense, I feel like Breakthrough Initiatives and Breakthrough Listen have probably done the most of anybody in their willingness to step in,” she continued. “It’s not just the money, but they’re really stepping in in a partnership way. They’re looking for ways to bring additional things here. They’ve actually taken some of our staff to California so they can understand better the other aspects of the project and so in terms of partnership, they have really been a fantastic group to work with.”

To learn more about Breakthrough Initiatives, visit

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