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Toasted Planets

August 15, 2013

The planets known as hot Jupiters are so close to their parent stars that their atmospheres are heated to many hundreds of degrees. But that proximity may also roast the planets from the inside out.

Such a planet is similar to Jupiter, the largest planet in our own solar system — a big ball of gas topped by a thick atmosphere. But it’s much, much closer to its star than Jupiter is to the Sun — typically only a few million miles.

The surfaces of these planets are extremely hot, causing their atmospheres to puff up. But some of these worlds appear to be hotter than they should be. A recent model says that’s because they’re also being heated from the inside out.

The model was developed by Derek Buzasi of Florida Gulf Coast University. It says that interactions between such a planet’s magnetic field and the “wind” of charged particles from its star channels energy into the planet’s interior. That creates electric currents that heat the planet’s center. Some of the heat radiates outward, making the planet’s surface even hotter.

Such currents also exist on Earth. But we’re far enough from the Sun that the currents are tiny, so they have little effect on our planet’s interior. Earth’s interaction with the solar wind does heat the outer atmosphere. Perhaps more impressively, it creates the northern and southern lights — beautiful displays of color that are energized by the Sun.

We’ll talk about a planet that cools down its star tomorrow.


Script by Damond Benningfield, Copyright 2013

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