Washington: Researchers have discovered 15 new planet candidates orbiting in the habitable zones of other stars.
Added to the 19 similar planets already discovered in habitable zones, where the temperature is neither too hot nor too cold for liquid water, the new finds suggest that there may be a "traffic jam" of all kinds of strange worlds in regions that could potentially support life.
Rather than being seen directly, the new planet candidates were found by Planethunters.org volunteers looking for a telltale dip in the brightness as planets pass in front of their parent stars.
One of the 15, a Jupiter-sized planet orbiting a Sun-like star, has been officially confirmed as a planet (with 99.9 percent certainty) after follow-up work with the Keck telescope in Hawaii and has been named "PH2 b".
It is the second confirmed planet to be found by Planethunters.org.
"There`s an obsession with finding Earth-like planets but what we are discovering, with planets such as PH2 b, is far stranger," Dr Chris Lintott, Zooniverse project leader from Oxford University, said.
"Jupiter has several large water-rich moons - imagine dragging that system into the comfortably warm region where the Earth is. If such a planet had Earth size moons, we`d see not Europa and Callisto but worlds with rivers, lakes and all sorts of habitats - a surprising scenario that might just be common," he added.
He study has been published in the Astrophysical Journal.