## 28 December 2012

### Astronomical Headline of the Year

Tell me that this was not the product of much giggles by the editorial staff:
Uranus takes a pounding more frequently than thought

Uranus isn't just gassy, it's also tilted completely sideways, such that instead of rotating like a spinning top, it rolls around the plane of the solar system more like a giant ball. Now astronomers think they know how this happened, and it means that Uranus has been pounded really, really hard not once, but twice.

Uranus' axial tilt of 98 degrees means that it's got one pole pointed almost directly at the sun, and one pole pointed out into space. As the planet revolves around the sun, these poles slowly switch places, meaning that if you lived there, you'd get 42 years of sunlight followed by 42 years of darkness, with a short time in between where things would seem almost normal.

Needless to say, this sort of behavior is a bit strange for Uranus, although nobody's quite been able to determine how it happened. New simulations from astronomers at the Observatory of Côte d'Azur in Nice, France may have just figured it out, and the answer seems to be that Uranus has suffered from not one but two giant impacts..
H/t LD at the Stellar Parthenon BBS.