The Impossible Planet

Astronomers at St. Andrews University have a puzzle. They have discovered a planet that shouldn’t exist. WASP-18b, as the mysterious object is known, is 10 times the size of Jupiter, yet it orbits just 1.4 million miles from its local star. (For comparison, Mercury’s orbit is an average of 36 million miles from the sun – NASA.) At that distance tidal forces should be dragging the unfortunate planet to its doom very swiftly. Have the astronomers been lucky enough to notice it just at the right time to witness its demise? Or is there something more complicated going on? The Independent is a bit breathless about the whole thing, but Sky & Telescope is very informative.

Naturally there are all sorts of plausible explanations for this. I’m sure that Al Reynolds could come up with a dozen without breaking sweat. But why? What are those darned aliens up to out there?