Astronomy: Strange alien world made of 'hot ice'

"A bizarre world of scorching hot ice shrouded in a steamy atmosphere may have been found, according to new observations. Characterising the Neptune-size planet is an important milestone on the way to detecting and characterising Earth-like planets that could harbour life....[T]he planet's width, which provides clues to its composition and structure...turns out to be about 50,000 kilometres wide, roughly four times the width of Earth and about the size of Neptune...too compact to be made mostly of hydrogen gas, like Jupiter, the researchers say, but not compact enough to be a rocky 'super Earth', as some had speculated. Instead, they believe it must be made mostly of an exotic form of water...the surface must be a blazing hot 300° C or more, keeping water in its atmosphere in vapour form. But the high pressures in the planet's interior would compress the water so much that it would stay solid even at hundreds of degrees Celsius – the expected temperatures inside the planet. There are a variety of exotic 'hot ice' states possible in such conditions, with names like 'Ice VII' and 'Ice X'...."

The rest of the story: New Scientist