Lighter than soap or even styrofoam, the largest gas giant yet discovered is in the constellation Lacerta that's "the lizard" and is so light it would float in a glass of water.....
The so-called HAT-P-1 orbits one of a pair of stars in the constellation Lacerta, about 450 light-years from Earth.
"This new planet, if you could imagine putting it in a cosmic water glass, it would float," said Robert Noyes, a research astrophysicist with the Smithsonian Astrophysical Observatory. The planet, a gas giant, is probably a puffed up ball of hydrogen and helium.
HAT-P-1 is an oddball planet, since it orbits its parent star at just one-twentieth of the distance that separates Earth from our own sun. While Earth takes a year to orbit the sun, the newly found planet whips around its star once every 4.5 days.
It may be that some of these planets, like those discovered by UC-Berkeley's Geoffrey Marcy, are 'failed stars' like some groups of disenfranchised people make up the 'failed states' of political dialogue.