Astronomers Map the Hot Weather on a Distant Planet

How’s the weather? Hot enough for you? Well, if you’re living on extrasolar planet HD 189733b, you’d really want to be anywhere else. That’s because the high noon temperatures reach 926 degrees C (1700 degrees F). How do we know what the weather’s like on this distant planet? Just thank Spitzer.

Astronomers working with NASA’s Spitzer Space Telescope have produced a rough map of the weather systems on HD 189733b. Over the course of 33 hours of observations, they gathered together more than 250,000 data points measuring the planet’s brightness. These data points were then mapped onto the planet, to show its global temperatures.

HD 189733b orbits its parent star at a distance of only 4.8 million km (3 million miles); it completes an orbit every 2.2 days. In terms of mass and size, it’s a little larger than Jupiter. This close proximity to its parent star puts it into the “Hot Jupiter” category, of extrasolar planets.

One interesting surprise: the hottest spot on the planet doesn’t directly face the star. Instead it’s offset about 30 degrees longitudinally. The researchers speculate that powerful weather systems redistribute the heat across the planet, and into these pockets of heat.

Original source: CfA News Release