Tuesday, March 14, 2006
Since yesterday, I've been skimming headlines about this new icy "super-Earth" discovered by the OGLE team using gravitation microlensing, thinking it was the same discovery I blogged about in January. Turns out it's another Neptune-mass terrestrial planet, this one more than twice as big and twice as close as the previous one. At 9K lightyears away, even if this new rock contains an ecosystem complete with sentient ice worms that 8999 years ago started sending radio signals, we're not going to be opening up any kind of meaningful dialogue. Still, as Andrew Collier Cameron, a planet hunter at St Andrews University, UK, points out in the New Scientist article linked above, “The fact that they’re picking up so many Neptune-mass planets is certainly interesting – it does suggest that they really are abundant.” The first half-dozen microlensing events have turned up two rocky planets, and that's a pretty good ratio. We've come quite long way from the idea of extrasolar planets being only hypothetical just a decade ago.