Dr. Frank Drake, a founding father of SETI, speaks during GBO inauguration ceremony
A great crowd was in attendance for the inaugural celebration of the Green Bank Observatory on October 8th, 2016. But among the speakers scheduled to appear that afternoon, perhaps none was more anticipated that Dr. Frank Drake, one of the earliest pioneers in the Search for Extraterrestrial Intelligence or SETI. Dr. Drake has fond memories of his time at Green Bank when he was one of only three scientists at the site.
“The mission of the observatory as established by the National Science Foundation and the National Research Council was to build the best and biggest radio observatory in the world,” said Dr. Drake. “And this was decided because it had been recognized that radio astronomy had become an important subject [that] only existed after WW II, that was growing rapidly and that had been developed very fast in Australia and the Netherlands and the Americans were lagging far behind.”
Dr. Drake said in the early days, government funding for projects was relatively easy to come by. But the technological challenges of building telescopes proved far more daunting. They were originally tasked with building both a 140 foot telescope and a 600 foot telescope, which would have been twice the size of the current Green Bank Telescope. However engineering problems with the 140 foot telescope, which would eventually be completed, made it clear that a 600 foot telescope would most likely remain a pipe dream.
“And so we very quickly had built an 85 foot telescope and we started using that and it produced some very good results,” said Dr. Drake. “Right away we measured the temperature of Venus, we discovered the radiation belts of Jupiter and a large number of external galaxies were detected through their nuclear hydrogen content.”
Dr. Drake had arrived at Green Bank in 1958. In 1960, he conducted the first organized search for extraterrestrial civilizations in an experiment known as Project Ozma. In 1961, Dr. Drake devised the well known Drake Equation, which provides a means for estimating the number of communicative extraterrestrial civilizations that we may be able to locate in our galaxy. More information about the Drake Equation is available here – http://www.seti.org/drakeequation
The Green Bank Observatory has come full circle back to the original aspirations of SETI with the Breakthough Listen Initiative. Dr. Andrew Siemion, Director of the Berkeley SETI Research Center spoke about the GBO’s role in the continuing search to discover if we are truly alone in the cosmos.
“We’ve discovered that planets in our own galaxy are very, very common,” said Dr. Siemion. “In fact we think that most stars that are in our galaxy have planets and something like 1 in 5 of those stars has a planet that exists in what’s called the ‘habital zone’ around the star. That’s the region around the star where liquid water could exist on the surface of that planet and life as we know it on earth could perhaps thrive.”
“We have fantastic telescopes like the Green Bank Telescope with beautiful surface accuracy, excellent pointing control and of course huge apertures to allow us to search for very, very weak signals.”
The Breakthrough Listen Initiative, founded by Yuri and Julia Milner and largely funded through private donations began operations in January of this year. Dr. Siemion said that the Green Bank Telescope is one of three identified so far to be part of the project. The other two are the Automated Planet Finder, an optical telescope in California, and the Parkes radio telescope in Australia. Twenty percent of the time on the GBT will be devoted to this project.
“The really special thing that happens when you pair very, very fast computers with very, very large telescopes is that you can conduct sensitive searches over a very wide portion of the radio spectrum,” said Dr. Siemion. “So in fact with our searches with the Green Bank Telescope now we can search billions and billions of radio channels compared with only a handful of radio channels that could be searched back in 1960.”
Two other scientists at the ceremony also spoke about the importance of the Green Bank Telescope in their research. Dr. Amy Lovell studies comets and said the GBT is a valuable tool when studying these bodies.
“These are the things that are the pieces of preserved material from back in the history of the solar system,” she said. “Here’s a picture of the most recent comet that’s been seen, and you see it’s a very complicated object. And there’s a lot that we want to learn from this; this is the piece of the history of the solar system here, but we can’t see that until we fly to it with a spacecraft. Well the Green Bank Observatory and the facilities here are going to allow us to understand what’s going on, on that piece of ice by looking at the gasses it produces.”
Dr. Scott Ranson, who received his Ph.d the same year that the GBT went online in 2001, said the telescope is unsurpassed in studying his favorite part of the universe, pulsars or spinning neutron stars. He said you can think of pulsars as very precise clocks that allow physicists to do very precise science. Like Dr. Lovell’s work, the GBT could also help answer questions about the workings of our universe as noted in this comment from Dr. Ranson.
“The center of our galaxy hosts a very, very massive black hole,” said Dr. Ranson, “about 4 million solar masses; we know that there should be neutron stars around there, and the GBT is our best hope right now of finding pulsars orbiting that black hole which would give us the best test of general relativity ever.”
Listening to these scientists it becomes abundantly clear the importance of the Green Bank Observatory not only to the scientific community, but also to the world as the GBO and its facilities continue to contribute to our understanding of the universe and our place in it.