Burning Down to Rock; May 2004; Scientific American Magazine; by Charles Choi; 2 Page(s)

The first rocky worlds astronomers detect circling other stars could resemble Inferno more than Earth. The existence of such lava-coated planets, which may prove commonplace, will force a reconsideration of theories about planetary formation.

Since 1991 observers have discovered some 120 exoplanets - worlds outside our solar system. All but three appear, by their great size and low density, to be gas giants. Roughly a sixth are "hot Jupiters" surprisingly near their stars, all closer than Mercury is to our sun.