NASA has been searching for alien planets for several years now. Learning about strange exoplanets such as enormous, hot "Jupiters" and "rogue planets" that actually cruise through space without a parent star certainly adds to the body of research concerning our universe. Yet what scientists are really interested in are the Earth-like planets that may hold the potential for life.
In order to detect these planets, researchers employ a variety of techniques, including gravitational microlensing. Microlensing actually measures the deflection of light from a distant star that passes through a planetary system en route to Earth--an effect that was first predicted by Einstein in 1936. This method allows scientists to detect planets that are roughly the size of Earth.
Yet the real powerhouse behind detecting planets was Kepler. The specially designed, three-foot diameter telescope, called a photometer or light meter, stared into space and collected substantial amounts of data. In total, Kepler confirmed 132 planets and spotted more than 2,700 potential ones, according to the Huffington Post.
Unfortunately for future research, though, Kepler has had a malfunction. The second of Kepler's four reaction wheels--devices that allow the observatory to maintain its position in space--has failed. This deprives Kepler of the ability to lock precisely onto its 150,000-plus target stars, according to Space.com. Needless to say, it's a huge blow for the planet-hunting mission.
Yet TESS may fill the void that Kepler has left behind. During its two-year survey, the observatory will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. These transits are another method for detecting exoplanets and occur when an alien planet briefly passes by its star, creating a shadow effect. TESS will hopefully identify planets ranging from Earth-sized to massive, gas giants.
In order to aid TESS with its search for life, astrobiologists are now modeling super-Earth atmospheres, planets several times Earth's mass, for planets orbiting in the habitable zone of red stars. By examining these atmospheres, scientists should be able to determine which planets are most suitable for life, according to Discovery News.
While modeling the atmospheres of these super-Earths, the researchers found that, in general, things could get messy. Ultraviolet radiation from a red dwarf is anemic. Without UV radiation to break apart certain gasses, a red dwarf planet might have a higher concentration of biosignature gasses and a smoggy sky. This means that super-Earth atmospheres probably won't look like anything that we would recognize immediately as behind habitable--and also means that scientists will need to be careful when pouring over TESS's data.
Currently, TESS is gearing up to target stars that will be 30 to 100 times brighter than those observed by Kepler satellite, which means that planets will be far easier to characterize with follow-up observations. Whether TESS will find a planet that supports life, though, is something that will have to be seen.
