NASA scientist Tom Barclay shared his recent discoveries with SDSU astrobiology students.
An artist's impression of the planets that Kepler has confirmed in the habitable zone. Relative sizes of all of the habitable-zone planets discovered to date alongside Earth. Credit: NASA
"Are we alone in the universe?"
Tom Barclay, a NASA scientist, began a lecture to the astrobiology class at San Diego State University with that question.
Barclay visited the class to discuss his research for the Kepler mission, including the discovery of a new planet that was announced last month.
Kepler is a NASA initiative that aims to detect Earth-like planets orbiting stars. Barclay recently led a team that discovered a new planetary system, including the first super-sized Earth-like planet that could possibly be habitable.
"This is an exciting time," Barclay said. "Before 1995, we didn't know much about planets beyond our immediate solar system. Now we're approaching on 1,000 planets."
Using the transit technique, Barclay and his team were able to locate the newly discovered Kepler-69c. The transit method is based on the observation of a star's small drop in brightness that occurs when the orbit of one of that star's planets passes in front of the star.
Locating Earth-like planets isn't an easy feat.
The transit probablity needs to be somewhere from 0.5-0.3 percent, which, according to Barclay, is rare. To track the transitions, one must continuously study multiple orbits of the same planet for as long as possible. This method proves to be both time consuming and expensive.
SDSU physics professor William Welsh explained the transit technique:
"Imagine a car's headlight off on a distant horizon. All you see is a dot of light. Now suppose a very small ant crawled across the headlight. Kepler would be able to detect that decrease in light."
Barclay, 27, grew up in the city of Sheffield in northern England. He obtained a bachelors degree in physics with astrophysics in 2006 and a master's of science degree in 2007 for his work to understand Galactic dust emission.
He moved to Northern Ireland for doctoral studies, where he worked with Gavin Ramsay at the Armagh Observatory. He was co-supervised, and was awarded his Ph.D. by the University College London in 2012. He worked on understanding the population of ultra-compact white dwarf binaries — systems with two stars that orbit each other in less than 10 minutes.
After postgraduate studies, Barclay was appointed to the Kepler Guest Observer Office at NASA Ames Research Center, California, as a staff scientist. He works to promote Kepler to the scientific community at large through the development of software and a dialogue. His scientific work focuses on pushing the limits of what can be done using the Kepler spacecraft.
Astronomy 310, or, "Astrobiology and the Search for Extraterrestrial Life," teaches students about new discoveries related to astrobiology, and aims to develop an understanding of the size, structure, origin, content and physical laws governing the universe. Students learn the basics of Earth biochemistry and use this knowledge to understand how astronomers are searching for extraterrestrial life.