ou know you have to have either done something horribly serious or be some top-secret investigator to be on the list of a government agency. In this case, you only need to be a star whose planets might be crawling with aliens.
Astronomers from Cornell University, Lehigh University and Vanderbilt University, led by Cornell’s Lisa Kaltenegger, a member of NASA’s TESS science team, have come up with the most likely planets something could be lurking on. The TESS Habitable Zone Star Catalog zeroes in on 1,822 cool stars (if you call 4,400-8,540 degrees Fahrenheit cool) that may be orbited by super-Earths which receive a level of radiation similar to our planet’s.
Kaltenegger heads the TESS program, searching for undiscovered planets in deep space by closely observing the stars in the catalog. TESS is an exoplanet hunter on a mission to observe 400,000 stars and identify new planets by glimpsing them as they transit across those stars. For 408 of them, TESS will be able to spot planets close in size and radiation level to Earth in just one transit. TESS is capable of identifying those factors and exploring the entire habitable zone of 227 of those planets, even to the cooler extreme. Think Mars in comparison to Earth.
“Life could exist on all sorts of worlds, but the kind we know can support life is our own, so it makes sense to first look for Earth-like planets,” Kaltenegger, whose team’s catalog was recently published in Astrophysical Journal Letters, said. “This catalog is important for TESS because anyone working with the data wants to know around which stars we can find the closest Earth-analogs.”
Some of the stars in the catalog are only 6 light-years away from Earth, meaning if there are any signs of life, we could be sharing a galaxy with something—or someone.
TESS needs to observe two transits to be sure it has both spotted a planet and figured out if it orbits in the habitable zone of its star. If aliens exist on any of these worlds, they are most likely to be hiding out on rocky planets that orbit their stars in a zone where water stays liquid. Such planets are also ideal targets for extremely large telescopes that are Earthbound, since their host stars are bright enough to recognize. NASA’s infamously delayed James Webb Space Telescope will eventually probe their atmospheres and further search for traces of anything that could be alive.
Does this mean aliens? Who knows. Does it mean a greater chance of aliens? Based on what we know about optimal conditions for life by Earth standards, yes.