Here I say, "And under that wouldn't be rock, but a form of high-pressure ice, like ice IX." 

I used ice IX to refer to the general category of high-pressure ices because it's a familiar term from Kurt Vonnegut's *Cat's Cradle*, but if GJ 1214b, the planet I'm discussing here, is in fact a water world, its most likely form is ice VII (and possibly ice X) due to the planet's predicted interior temperatures. See the upper left of this [water phase diagram](http://ergodic.ugr.es/termo/lecciones/water1.html).

サラ・シーガー: 太陽系外の惑星を求めて

太陽系外の惑星を求めて

どの夜空に輝く星にも、少なくとも１つの惑星が回っています。この太陽系外の惑星について、どのような知識があり、さらに学ぶには何が必要なのでしょう？天文家のサラ・シーガーが、興味深い幾つかの系外惑星と、情報収集に使われる新しい技術を紹介します。この技術で生命体の住む系外惑星も見つけられるかもしれません。

Recent discoveries reveal that every star in the night sky hosts at least one planet, and the Milky Way alone teems with billions. Astronomers are now on the brink of identifying planets with conditions similar to Earth. Using innovative tools like the starshade, researchers are developing ways to study distant atmospheres for signs of life. This search may soon answer humanity’s oldest question: are we alone in the universe.