NASA’s Kepler telescope continues the search for life-sustaining planets


In January, NASA’s Kepler space telescope made a series of important discoveries about the existence of life-sustaining planets in the Milky Way galaxy.

Currently, NASA’s official Kepler website reports 1,013 confirmed planets, and this month NASA’s Kepler space telescope brought news of eight more planets lying in what scientists refer to as the “habitable zone” or, more colloquially, the “Goldilocks zone.” Planets in the “Goldilocks zone” are neither too close nor too distant from their suns (too close and water evaporates, too far and water freezes).

Two of the newly discovered planets, Kepler-438b and Kepler-442b, are the most Earth-like in terms of size and distance from their stars.

Kepler-438b has a 70 percent chance of being rocky, a planetary feature widely assumed to be necessary for life as most of the planets found throughout the universe are often surfaceless gas giants. Another important life-sustaining feature that 438b and 442b seem to share is size, which appear massive enough to have the gravity to support an atmosphere.

Kepler, named after the German astronomer who established the three scientific laws of planetary motion, has been hard at work searching for these “exoplanets” since 2009. In 2013, scientists used all the data collected by Kepler to estimate that there may be 40 billion such habitable planets throughout the Milky Way.

Kepler’s targeted area of search. Image courtesy of

Kepler orbits our sun while taking photographs of far-off stars and planets hundreds or even thousands of light years away. It’s main instrument is a photometer, which is “a Schmidt telescope design with a 0.95-meter aperture and a 105 square deg (about 12 degree diameter) field-of-view (FOV). It is pointed at and records data from just a single group of stars for the three and one-half or more year duration of the mission.” Scientists then analyze the data collected from Kepler for impossibly minute changes in brightness. These changes in brightness occur when a smaller planet passes in front of a larger star.

In a recent interview with Truthdig, NASA co-investigator Douglas Caldwell explained that Kepler’s task is analogous to looking at the Empire State building with all the lights on and window shades drawn, “[When] someone lowers one of the window shades by [just]a few inches, [this]change in brightness” is what Kepler is looking for when planets pass by stars.

Kepler’s photometer in an image from NASA

Caldwell went on to explain that Kepler is slowly drifting away from Earth and will eventually fall so far behind that scientists will be unable to communicate with the telescope.

Although NASA is better known for finding planets and calculating Barney Gumble’s bar tab than coming up with creative names for planets, studying these planets in greater detail will not happen for a very long time. This is due in part to the vast distances that separates us from them. For example, Kepler-438b is roughly 475 light-years from Earth. Even if there were civilizations on Kepler-438b that could receive radio waves, it would take hundreds of years before they could hear some of our first signals.

“Kepler 64,” by Dirk Terrell, winner of NASA’s Art of Discovery Contest. Image courtesy of

The best that we can hope for is launching more powerful telescopes and far reaching probes into space. Both of which NASA is already working to make happen.

About Author

Adam Cameron spent his academic career learning about Iran, but ultimately decided that a job in the military-security-industrial complex just wasn't for him. He worked with Iranian refugees for a few years and has always dreamed of being a writer. He lives in North Hollywood, California in an 8-bit cocoon made out of an elaborate blanket fort covered in Adventure Time posters.

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