https://edition.cnn.com/2020/03/27/world/uranus-plasmoid-voyager-2-scn/index.html
Only one spacecraft has flown near Uranus and Neptune, the mysterious ice giant planets on the edge of our solar system.
Yet the wealth of data captured by NASA’s Voyager 2 spacecraft some 34 years ago is still revealing tantalizing hints and reminding scientists of why we need to go back.
Voyager 2 flew by Uranus in 1986, and now, thanks to a little blip discovered in some data, NASA scientists know it also flew through a plasmoid. A plasmoid is a giant magnetic bubble that likely pinched off part of the planet’s atmosphere, sending it out into space.
They found it while looking through old data to find questions they wanted to answer on future potential missions to Uranus.
It’s not unusual for planets to lose their atmospheres. Venus, Jupiter, Saturn and even Earth leak their atmospheres into space, according to NASA.
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NASA wants to return to investigate the planet’s oddities, and DiBraccio and Gershman were part of a team looking at designing a future mission to revisit the ice giants.
A 60-second zigzag in Voyager 2’s magnetometer readings, which measured the strength and direction of the planet’s magnetic field, revealed what looked like a plasmoid to them. It’s the first time one has been detected escaping Uranus.
In this case, the giant plasma bubble full of energized hydrogen detached from the magnetotail. It truly is like the tail end of the magnetic field, which is pushed off of the planet by the sun.
The plasmoid, which resembled a cylinder, was 127,000 miles long and 250,000 miles across. Inside the plasmoid, they observed loops — shaped by the planet’s spin as they released into space.
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