Where are the Giants?

Perhaps the biggest revelation in the world of exoplanets in 2012 has been Kepler’s stunning data sets, which show that small, rocky, Earthlike planets may be some of the most common in the galaxy – perhaps one for every star.

But what about larger planets, like Jupiter in our own solar system, or the many so-called “Hot Jupiters,” gas giants that orbit punishingly close to their stars? Worlds like these were among the first ever discovered by planet-hunters, and, until the Kepler mission, were the most common type of exoplanet detected.

A group of astronomers including John Johnson of Caltech has found that data from Kepler may show that Jupiter-size planets might not be as easy to come by as smaller, rocky worlds like Earth.