Although astronomers have identified more than 130 planets beyond the solar system, these alien worlds remain phantoms. Too faint and small to be imaged, each planet has been detected only indirectly, either by the wobble it induces in its parent star or by the tiny amount of light it blocks when it passes in front of its star.
This week, two extrasolar planets stepped out of the shadows. Two teams of scientists announced at a NASA press briefing that they have for the first time directly detected the heat emitted from planets that circle sunlike stars more than 100 light-years from Earth.
"These are really epochal discoveries," comments Alan Boss of the Carnegie Institution of Washington (D.C.) "We're entering a new regime of planet detection."
The observations do