GUADALAJARA, Mexico – A multimillion-dollar campaign to look for evidence of extraterrestrial civilizations has added telescopic observations of the nearest known exoplanet, Proxima Centauri b, to its agenda.
Last month’s announcement about the detection of Proxima b caused a sensation because scientists said the planet is only a little more massive than Earth, orbiting in the habitable zone of Proxima Centauri, the red dwarf star that’s closest to our own solar system. That put Proxima b at the top of the list of prospects in the search for life beyond the solar system.
It may take a decade or two, but the Breakthrough Prize Foundation says it is looking into the options for direct imaging of Proxima b, a mere 4.3 light-years away,
The foundation’s chairman, former NASA official Pete Worden, said there’s a chance of gaining more information about Proxima b and its parent star through the use of 8-meter telescopes such as the Gemini North and Keck observatories in Hawaii, or the Gemini South and Very Large Telescope facilities in Chile.
“We’re in discussions with people working on that,” Worden said last week at the International Astronautical Congress in Guadalajara. “But probably the most interesting thing is the next generation of large telescopes, particularly the European Extremely Large Telescope, which is 39 meters, the Giant Magellan Telescope … and the Thirty Meter Telescope, if we can assuage the gods in Hawaii.”
If those telescopes are equipped with coronagraphs to block out the infrared glare of its parent star, they should be good enough to get an image of the planet by itself, Worden said. What’s more, spectral observations could tell scientists whether Proxima b’s atmosphere contains gases whose presence is consistent with biological activity.
“That’s an example of something we can do to determine, is there life on those planets? Do you see signals for water, oxygen, other potential volatiles that indicate life?” Worden told GeekWire. “That’s the kind of discussion we want to do. There are other ideas about polarized light and so forth. We think in the next decade, from ground-based systems and eventually space-based systems, we can really study intensively this planet, and get some of those answers.”
The Breakthrough Prize Foundation, founded by Russian billionaire Yuri Milner, already has two $100 million initiatives looking into the prospects for life beyond our solar system.
One is called Breakthrough Listen, and involves using three telescopes to scan the skies for radio or optical signals from a million star systems.
The other is Breakthrough Starshot, which is designing a fleet of laser-powered nanoprobes to fly through the Alpha Centauri star system, potentially including Proxima Centauri.
Worden said the Chilean government already “has asked us to come and talk with them” about building the system’s laser-beaming array. He said the current plan calls for building a sub-scale prototype, and then establishing a public-private partnership to construct a full-scale, kilometer-wide array.
Worden expected the cost of the full-scale system to be “roughly equivalent to the Large Hadron Collider at CERN, or the James Webb Space Telescope.” The LHC’s estimated cost is $10 billion, and the Webb telescope’s cost is roughly $9 billion.
Worden said the Breakthrough team conducts a series of annual conferences to discuss its agenda. “This year we’re going to focus on Proxima b: What can we learn about Proxima b … with remote sensing?”
Some scientists involved in the consultations have told GeekWire privately that the focus on Proxima Centauri b will be in support of the Starshot initiative, but could be expanded into a wider initiative informally known as Breakthrough Watch.
Facebook founder Mark Zuckerberg and Google co-founder Sergey Brin have teamed up with Milner on past Breakthrough projects, and backers of that caliber are reportedly in on the consultations about Breakthrough Watch.
In an email exchange, Worden declined to comment about future steps other than to say “we are working several possibilities.”
Theoretically, Breakthrough could give a boost to the mega-telescope projects that are already under development, or support new efforts that are maximized to observe Proxima b and other close-in exoplanets.
If Proxima b is positioned so that it moves across Proxima Centauri’s stellar disk, there’s a chance that observatories including NASA’s yet-to-be-launched James Webb Space Telescope could study its atmosphere by watching how the spectral characteristics of starlight change over time.
Based on the currently available information, that’s judged to be a long shot. However, bigger telescopes could look for the planet’s reflected infrared glow. If the spectral fingerprint of that glow changes over time, astronomers could conceivably analyze Proxima b’s atmosphere and perhaps even map out its cloud patterns or heat patterns.
One proposed project, known as the Colossus Telescope, would look for the heat signature of extrasolar life and alien civilizations. The project calls for using low-cost mirror fabrication techniques to build the equivalent of a 74-meter telescope, at a cost estimated in the range of $500 million.
Some of the Colossus project’s organizers are currently raising money for a smaller telescope called PLANETS (“Polarized Light from Atmospheres of Nearby ExtraTerrestrial Systems”). One of those organizers, University of Hawaii astronomer Jeff Kuhn, is on the Breakthrough Foundation Watch Advisory Board – but he stressed that the foundation hasn’t made a commitment to back PLANETS or Colossus.
