New discoveries from NASA’s Kepler space mission made public Wednesday reveal a large and surprising menagerie of planets deep in space, with some almost as small as Earth and others in the “habitable zones” of their solar systems where scientists think life could exist.
With about 1,200 candidate planets now cataloged, Kepler has also identified a solar system, called K-11, with at least six small planets orbiting their sun — all lined up on a disclike plane similar to our own.
The planets — called exo planets because they are outside Earth’s solar system — are believed to be gaseous rather than rocky and thus unable to support life, but the discovery of a system with so many planets orbiting in a manner similar to planets in our system has created great excitement.
“This is a remarkable system and a very exciting sign of what else is to come,” said Jonathan Fortney, a member of the Kepler science team from the University of California at Santa Cruz. “Given the information Kepler is sending back, we’re not only able to identify the planets, but we can tell a lot about how big they are, how close they are to their suns and to some extent what they’re made of.”
The results, released at a NASA news conference, and the journal Nature report on a little more than a quarter of the information collected by Kepler, launched almost two years ago.
The unprecedented job of the space telescope is to observe a small section of deep space to determine how many Earth-size planets exist there, how many suns like our own have planets and how many of those planets might be in habitable zones. The ultimate goal is to assess whether some planets can, or do, support life.
Because of the technique used by Kepler to find the exoplanets, those identified so far are usually closer to their suns than Mercury is to our sun, with orbits of a few months to a few days. As Kepler collects information over a longer time, planets farther from their suns will be identified, and those are the ones expected to be rocky, watery and potentially more hospitable to life.
The Kepler space telescope detects planets that pass in front of their stars (or “transit”) and thereby cause a tiny periodic dip in the brightness of the star. The amount of reduced brightness lets scientists know how large the planet is in terms of its radius while the time between transits reveals the speed of its orbit.
