The search for extraterrestrial life, especially sentient beings, gets a big boost every time astronomers find new planets. The more planets found, the more chances of finding an extraterrestrial "footprint," or signs that the planet may be inhabited. With telescopes like Kepler scanning the skies from space and the additional range and power afforded scientists through interferometry (the linking of radio telescopes to form one large telescope), the number of planets that scientists can study has been increasing rapidly over the past few years. On September 12, the European Southern Observatory (ESO) announced the discovery of more than fifty exoplanets, 16 of which are super-Earths, rocky planets like our own that are as massive as ten times the Earth's size. And one of those planets is located in the "Goldilocks Zone."
The historic find, the most super-Earths ever announced in a single discovery, is the result of two years of work using HARPS (High Accuracy Radial Velocity Planet Searcher, or HARPS), ESO's major planet hunter located at La Silla Observatory in Chile. Even more exciting for astronomers and astrobiologists was that one of the super-Earths was a candidate for Earth-like conditions and possible habitability. That planet, HD 85512 b, which is about 35 light years from Earth in the constellation Vela, orbits the star HD 85512 just on the inside of its habitable -- or "Goldilocks" -- zone, scientists believe, and just might support life.
And it is indeed a super-Earth, measuring 3.6 times the size of our own world, according to Space.com. It has a surface temperature of 77 degrees Fahrenheit and just might present with the right conditions for water to form, therefore making it able to harbor life.
Michel Mayor, leader of the HARPS team, said in a statement: "In the coming 10 to 20 years we should have the first list of potentially habitable planets in the Sun's neighbourhood. Making such a list is essential before future experiments can search for possible spectroscopic signatures of life in the exoplanet atmospheres."
But that is life as we understand it. Given the complexity of life on our own planet, where creatures and microorganisms live in the most exotic locations, it is difficult to say which planets may or may not be habitable. Although scientists limit searches for extraterrestrial life to planets like our own when assessing for habitability (call it "species bias"), it is quite possible that alien life -- including intelligent alien life -- might exist on worlds with atmospheres of methane. Or without water, for that matter.
But the present search parameters are geared toward finding exoplanets that resemble Earth-like conditions as closely as possible in the hope that such favorable conditions as spawned life here did so on some far-flung alien world as well.
At present, counting the more than 50 new planets, there are over 600 planets to study. NASA lists 564 confirmed worlds on their PlanetQuest website (which currently excludes the newly announced ESO batch). It should also be noted that there are over 1,200 exoplanet candidates that have been identified by NASA's Kepler mission.
(photo credit: Frank Lewecke, Creative Commons)