The largest known planet in the universe, TrES-4, described for the first time last August, is a real head scratcher. This giant has about five times the volume of Jupiter but only four-fifths the mass. Given a 151,000-mile-wide bathtub, the planet could float on water. TrES-4 is so large and light that it challenges existing ideas about planet formation, says Georgi Mandushev, an astronomer at the Lowell Observatory who led the team that found the planet. “This planet is impossibly big,” he says.
But for the modern-day planet hunter, breaking records is all in a day’s work. The discovery of TrES-4 comes only months after the news of Gliese 581c, the smallest planet discovered outside our solar system. To top it off, nearly 40 discoveries this year have swollen the ranks of exoplanets to about 250, up by 20 percent.
The rapid rate of discovery of exoplanets can be attributed ...
