May 25, 2017

NASA's Juno probe reveals chaos on Jupiter

J.E.P. Connerney et al., Science (2017)

The first science results are in from NASA spacecraft Juno's close pass over Jupiter last summer:

  • There are huge cyclones up to 870 miles in diameter at both of Jupiter's poles, which appear to be chaotic and violent.
  • Jupiter's gravitational field is massive - roughly 10 times Earth's magnetic field and greater than what NASA scientists had expected.
  • There's quite a light show on the gas planet. Juno detected electron beams showering energy downward into Jupiter's upper atmosphere, which may be what powered the huge aurorae the probe saw in ultraviolet and infrared images it captured.
  • Unexpectedly, there are signs of ammonia welling up from its deep atmosphere, indicating a giant weather system across the planet.

Big differences: One thing is clear from the first actual looks at Jupiter's surface and atmosphere: it's no Earth. The differences in electron showers between the two planets suggest they behave very differently with their space environments.

How it works: The Juno spacecraft launched in 2011, and made its first close pass of Jupiter on August 27, 2016. Juno was able to fly just above the cloud cover, as low as 2,100 miles above the surface of the planet, and captured time-lapse images of the poles, revealing the enormous cyclones at them. It was also able to measure the thermal structure of Jupiter's atmosphere.

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America's future looks a lot like Nevada

Illustration: Sarah Grillo/Axios

Today's Nevada caucus will foreshadow the future of American politics well beyond 2020.

Why it matters: The U.S. is in the midst of a demographic transformation, and the country's future looks a lot like Nevada's present. Today's results, in addition to shaping the 2020 race, will help tell us where politics is headed in a rapidly changing country.

Coronavirus spreads to more countries, and U.S. ups its case count

Data: The Center for Systems Science and Engineering at Johns Hopkins, the CDC, and China's Health Ministry. Note: China numbers are for the mainland only and U.S. numbers include repatriated citizens.

The novel coronavirus continues to spread to more nations, and the U.S. reports a doubling of its confirmed cases to 34 — while noting those are mostly due to repatriated citizens, emphasizing there's no "community spread" yet in the U.S. Meanwhile, Italy reported its first virus-related death on Friday.

The big picture: COVID-19 has now killed at least 2,359 people and infected more than 77,000 others, mostly in mainland China. New countries to announce infections recently include Israel, Lebanon and Iran.

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