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Yes, it is hot outside, and, yes, it happens every summer. But we are about to learn about an unusual temperature spike over Jupiter's Great Red Spot. Scientists have just discovered it, and they think they know what's heating things up. NPR's Nell Greenfieldboyce reports.
NELL GREENFIELDBOYCE, BYLINE: Jupiter's Great Red Spot is a vast storm that stretches over 10,000 miles. It's a rotating mass of clouds that's bigger than Earth.
JAMES O'DONOGHUE: It's the largest storm in the solar system. I guess, really, it's the largest storm we know about anywhere so far.
GREENFIELDBOYCE: James O'Donoghue is a researcher at Boston University. He says this storm has screaming winds that blow up to 350 miles per hour. And while a storm on our planet might last just hours or days...
O'DONOGHUE: On Jupiter, you have this massive storm that's existed for as long as we can measure it, for over 300 years now.
GREENFIELDBOYCE: O'Donoghue recently realized that the Great Red Spot could help solve a mystery about gas giant planets. Scientists haven't been able to explain why their upper atmospheres are so darn hot.
O'DONOGHUE: Essentially all of the gas giants' upper atmospheres are measured to be several hundred degrees warmer than they should be based on simulations of heating from the sun.
GREENFIELDBOYCE: To try to understand where the extra heat was coming from, he and some colleagues decided to map out the temperatures across Jupiter's upper atmosphere. They were looking for any hot spots. And, lo and behold, they found one right over the Great Red Spot. In the journal Nature, they say the area above the storm is way hotter than surrounding regions by about 1,000 degrees Fahrenheit.
O'DONOGHUE: So the difference is very large and very real.
GREENFIELDBOYCE: Here's how he thinks this storm puts on the heat - as the churning clouds and gases whack into each other, they create a deafening roar. The sound waves travel hundreds of miles up and crash into particles in the upper atmosphere, kind of like crashing waves on a beach.
AMY SIMON: It's certainly intriguing. I think it's something that warrants a bunch of follow-up.
GREENFIELDBOYCE: Amy Simon is a planetary scientist at NASA's Goddard Space Flight Center in Maryland. She says scientists know so little about the Great Red Spot. They're not sure what formed it or why it sticks around or even why it's red.
SIMON: We have a guess as to what the clouds are made of, but we don't have direct evidence of that either.
GREENFIELDBOYCE: She says we should learn more about this epic storm from NASA's Juno spacecraft, which will orbit and study Jupiter for nearly two years. It just arrived at the gas giant earlier this month. Nell Greenfieldboyce, NPR News.
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