Looking for Life? Pick your Exoplanet
If you are searching for life in the universe, it's nice to know where to look. NASA now has enough data on exoplanets to narrow down that search. Two classes of planets exist around distant stars -- and one of those classes has planets remarkably like Earth.
This week NASA revealed ten new places where life might thrive. The information coincides with NASA's Kepler Exoplanet Week.
Astronomers added 219 new planet candidates to the exoplanet archive, mostly from the constellation Cygnus. Ten of these candidates are of earth size or larger and inhabit zones of the solar system that allow for liquid water to exist on the surface. The number of life-possible exoplanets continues to increase.
Exoplanets are those that orbit stars other than our sun. When these planets move between the earth and the star, the light from the star diminishes. The Kepler space telescope finds these periods of transit and sends the information to earth, which makes possible a more detailed examination.
Astrophysicists then glean more precise data on exoplanet transits using telescopes like the W. M. Keck in Hawaii. New data brought startling revelations. Exoplanets are either rocky like Earth or Mars, or gaseous like Neptune. Surprisingly, there don't seem to be many, if any, in between. And if a planet is rocky, there is a good chance that it is 75% larger than Earth.
Looking for life? These are prime places to look.
The science of exoplanet research has been growing since the first planets beyond our solar system were discovered. Delightfully, any member of the public can look at the same data scientists use, because NASA keeps a database of all the exoplanets.
We know of 3,496 confirmed exoplanets, including 582 multi-planet systems, with scientists adding more all the time. New information on the growing list of planets and planet candidates was discussed at the NASA's Ames Research Center in California just this week by scientists of the Astrophysics Division of NASA's Science Mission Directorate.
Benjamin Fulton and his colleagues at the University of Hawaii in Manoa used data from the Keck telescope to ascertain that two classes of planets exist.
NASA placed the Kepler space telescope into orbit in March 2009 with an express mission to locate planets orbiting other stars. In an age of complex instruments, Kepler is unique. It contains only a single photometer. This instrument scans the skies for main sequence stars and looks for the dimming that occurs during exoplanet transit. Data reveals Kepler Objects of Interest (KOI), which are later upgraded to Kepler planet candidates. Then, astronomers use telescopes on earth, like the Keck, to confirm that a candidate is an exoplanet.