A Japanese-U.S. joint research team has found a planet covered by a thick layer of gas like Jupiter but which has an unusually large core of rocks and ice -- a discovery scientists say could overthrow the established theory of planet formation. The planet, belonging to the Hercules constellation about 250 light years away from Earth, does not fall into the category of either Jupiter-type, gas-covered planets that have low density, or high-density, Earthlike planets.The discovery, made by a research team including experts from the National Astronomical Observatory of Japan (NAOJ) and San Francisco State University, was reported in the July 1 issue of Astrophysical Journal, a U.S. science magazine.The research team used Japan's Subaru telescope in Hawaii to observe the planet when it passed a fixed star. By analyzing the fixed star's light as the planet passed it, the team successfully clarified the density and size of the planet.The mass of the planet is 1.2 times that of Saturn but its diameter is only 0.86 times that of Saturn, meaning it is dense and covered in a thick layer of gas. The mass of its core, made up of Earthlike rocks and ice, is 70 times that of Earth.It is one of several planets whose structures have been defined from among about 150 plants outside the solar system.If the mass of the core of a planet that consists of rocks reaches 10 to 20 times the mass of Earth, its gravity is believed to gather massive amounts of gas, thereby forming a planet covered by a thick layer of gas, just like Jupiter and Saturn, according to Associate Prof. Shigeru Ida, a member of the team. Scientists believe this layer of gas prevents rocks from entering the planet's surface from outside.
View: Full Article | Source: MDN
Interesting, I am sure that as we explore the Universe we will find many things that are new and not what Science has predicted. It's these Unknowns that drive's Man in to Space in the first place.