Earthlike planets may be common Thu Sep 7, 7:42 PM ET WASHINGTON (Reuters) - Earthlike planets covered with deep oceans that could harbor life may be found in as many as a third of solar systems discovered outside of our own, U.S. researchers said on Thursday. These solar systems feature gas giants known as "Hot Jupiters," which orbit extremely close to their parent stars -- even closer than Mercury to our sun, University of Colorado researcher Sean Raymond said. The close-orbiting gassy planets may help encourage the formations of smaller, rocky, Earthlike planets, they reported in the journal Science. "We now think there is a new class of ocean-covered, and possibly habitable, planets in solar systems unlike our own," Raymond said in a statement. The team from Colorado, Penn State University and NASA's Goddard Space Flight Center Maryland ran computer simulations of various types of solar systems forming. The gas giants may help rocky planets form close to the suns, and may help pull in icy bodies that deliver water to the young planets, they found. "These gas giants cause quite a ruckus," Raymond said. Water is key to life as humans define it. "I think there are definitely habitable planets out there," Raymond said. "But any life on these planets could be very different from ours. There are a lot of evolutionary steps in between the formation of such planets in other systems and the presence of life forms looking back at us." As many as 40 percent of the 200 or so known planets around other stars are Hot Jupiters, the researchers said.