NASA confirmed the existence of five more Earth-like planets Wednesday after Belgium-operated telescope TRAPPIST discovered two in 2016, providing astronomers with the first concrete opportunity to search for intelligent life outside of the solar system.
UC Berkeley astronomers from the Berkeley Search for Extraterrestrial Intelligence (SETI) Research Center are also searching for planets that may contain intelligent life. According to campus astronomy professor Alex Filippenko, the Automated Planet Finder telescope located at the university-owned Lick Observatory has observed a few new planets in the past, but none quite as “amazing” as the seven recently discovered planets.
The seven planets are located at about the right distance from their host star TRAPPIST-1 to have the same temperature as Earth, making the existence of water on their surfaces a possibility, according to a study published Thursday in the scientific journal Nature. TRAPPIST-1 is 40 light years, or about 235 million miles, from Earth, according to NASA. Scientists have classified it an “ultra-cool dwarf” star, meaning that it is cool and relatively small in size — only 4,150 degrees Fahrenheit compared to Earth’s approximately 10,000-degree sun. It has about eight percent of the mass of the sun and its dim radiance makes observing it with a telescope much easier.
NASA’s James Webb Space Telescope, set to launch in 2018, could provide astronomers with additional data regarding the amount of water, methane and oxygen in TRAPPIST-1’s atmosphere.
The Breakthrough Listen Initiative, a scientific search for extraterrestrial life, is working within SETI to make astronomical data available to the public.
“The study released is a great interest to us because many of the best places to look for life are on planets where the conditions might be right for life,” said Steve Croft, campus astronomer and a member of the Breakthrough Listen Initiative.
According to Andrew Siemion, director of SETI and the Breakthrough Listen Initiative, SETI looks for “artifacts of intelligence” on foreign planets in various forms because there is no way to detect life at interstellar distances using the direct methods that researchers might use to explore life on Earth.
“We are attempting to answer what we believe to be humanity’s oldest and most profound question,” Siemion said.
Siemion explained that human technology produces signals that are noticeable at interstellar distances, particularly electromagnetic emission from radios, airplane signaling and other technology. According to Siemion, when those signals leave Earth, another intelligent civilization in the galaxy would be able to detect human existence, provided that the extraterrestrial civilization also had radio telescopes. Conversely, SETI uses telescopes to detect potential emission from extraterrestrial technology, based on the assumption that there does exist other intelligent life elsewhere in the galaxy, Siemion said.
Members of the Breakthrough Listen Initiative viewed TRAPPIST-1 on their telescope soon after NASA’s discovery. According to Siemion, observations of objects are made less sensitive when they are close to the sun — it is best to view objects when they are as far away from the sun as possible, Siemion said.
“(TRAPPIST-1 was) very close to the sun, so it’s not really an opportune time to observe it, but we happened to have an observing session at the right time to observe it, so we took a small amount of data and we will take more when it’s a better time,” Siemion said.