Oh, many thousands and thousands. And we've only just begun to find them all.
A photo may be worth 1,000 words, but a new depiction of NASA's Kepler mission is worth 1,235 potential alien planets. Created by a devoted mission scientist, the image takes stock of the Kepler observatory's prolific planet-hunting results so far.(from Fox News)
The illustration shows all of Kepler's candidate planets — which await confirmation by follow-up observations — crossing the face of their host stars. This provides scale, and it's also a nod to Kepler's planet-hunting strategy: The spacecraft detects alien worlds by measuring the telltale dips in a star's brightness that occur during these planetary "transits."
The graphic is the brainchild of scientist Jason Rowe, who created it in an attempt convey Kepler's exoplanet discoveries to the masses in a clear, concise manner.
"The graphic itself has been great to show to people. There is lots of interesting astrophysics that one can present," Rowe, a member of the Kepler team at NASA's Ames Research Center and the SETI (Search for Extraterrestrial Intelligence) Institute, told SPACE.com. "My favorite one so far is that planets can be just as big as some of the smallest stars."
In Rowe's graphic, the parent stars of Kepler's potential alien worlds are arranged by size, with the largest at the top left of the diagram and the smallest at the bottom right. For reference, our own sun is shown sitting by itself, just beneath the top row. Both Jupiter and Earth are depicted transiting the sun in the illustration, researchers said.
They're out there, all those planets, just waiting for us to get out there to them. Now, let's find a way to get going.