NASA finds mysterious "hidden" planet

NASA's Kepler mission continues to discover new, mysterious planets in the depths of space, with the space telescope identifying an "unseen" Super-Earth thanks to its blocking of a distant star. Kepler identifies possible planets from their repeat movement in front of stars, tracking the periodic dimming of the star itself rather than attempting to spot the much darker planet. Parent star KOI-872 (Kepler Object of Interest no.872) had shown a surprising erraticism in its dimming, MSNBC reports, with the actual movement varying by up to a few hours.

Kepler had originally indicated a single planet in orbit around KOI-872, with a transition period of once every 34 days. "The planet should show transits equally spaced, which is not the case," astronomer David Nesvorny of the Southwest Research Institute in Boulder, Colo. said of the research. "Sometimes the transit is two hours late, sometimes two hours early."

Computer modeling suggested the time difference could, in fact, be because of a second planet in orbit, much closer to the sun than the first. In fact, astronomers believe there's a 99-percent chance of a second, Saturn-sized object orbiting the sun every 57 days; "this is the first occasion where there is great confidence that the [computer modeling] method works" Nesvorny says.

The scientists have now moved on to identifying so-called exomoons, which orbit planets just as our own moon orbits the Earth.

NASA recently secured a new round of funding for Kepler, which will see the mission – described as "an outstanding success" – continue to run through to the end of 2016. The goal is to locate planets which could potentially support life.