SETI observations of 'exo-Earth' Ross 128b

Exciting news: the HARPS exoplanet hunter team have discovered a new, Earth-like exoplanet orbiting around the star Ross 128, one of our closest neighbors. This newly discovered 'exo-Earth', designated Ross 128b, is particularly remarkable as it is thought to have surface temperatures similar to here on Earth.

Curiously, this is the second time this year Ross 128 has been in the news. In May 2017, an intriguing signal in the direction of Ross 128 was detected at Arecibo. In July, we conducted follow-up observations with Green Bank Telescope and concluded that disappointingly, the signal was most likely due to radio interference from a passing satellite. Our analysis has now been accepted for publication in the International Journal of Astrobiology; data from our observations is available for download at http://seti.berkeley.edu/ross128/.

Ross 128 was also observed over the 1.1-1.9 GHz band as part of Breakthrough Listen's nearby star survey. Again, we did not detect any signals of SETI interest. These data are available online, and our analysis is detailed in the Astrophysical Journal (E. Enriquez et. al., 2017).

So sadly, we've already looked closely at Ross 128 and have come up empty. Nonetheless, as Ross 128b is such an exciting target, we are considering additional, deeper observations at radio and optical wavelengths. Nearby exoplanets are particularly exciting from a SETI perspective as they permit us to search for and potentially detect much weaker signals than from more distant targets.

While our search for intelligent life has yet to turn up any evidence, Ross 128 b is an ideal candidate for ESO's upcoming Extremely Large Telescope, that will be capable of detecting so-called biomarkers in the atmospheres of nearby exoplanets.

Ross 128 b is further confirmation of the ubiquity of life-supporting environments throughout our galaxy, and indeed the universe. We know that everything necessary for life to emerge and thrive is present in abundance, but whether or not life has emerged elsewhere in the universe remains a tantalizing unknown.

Image: Ross 128, Sloan Digital Sky Survey