NASA scientists believe that Uranus may be leaking
While examining 30 year old data from the Voyager 2 mission, scientists at NASA discovered that Uranus is leaking its atmosphere due to a magnetic bubble.
As 4WWL reports:
NASA said that Voyager 2 may have flown through what is called a plasmoid when it zipped past Uranus on January 24, 1986. Voyager 2's flyby is the only close encounter an Earth-based probe has had with the seventh planet from the sun.
"These giant bubbles of plasma, or electrified gas, pinch off from the end of a planet’s magnetotail — the part of its magnetic field blown back by the Sun like a windsock," NASA writes. "With enough time, escaping plasmoids can drain the ions from a planet’s atmosphere, fundamentally changing its composition."
Space physicists Gina DiBraccio and Dan Gershman with NASA’s Goddard Space Flight Center believe the plasmoid could account for between 15% and 55% of atmospheric mass loss at Uranus. That's more than either Jupiter or Saturn.
DiBraccio and Gershman believe Uranus' plasmoid is a cylindrical shape at least 127,000 miles long and up to 250,000 miles across. It's likely charged with mostly ionized hydrogen particles.
To be fair, all planets leak atmosphere into space -- even Earth. It just happens very slowly. DiBraccio notes that Mars used to be a wet planet with a thick atmosphere. Four billion years of atmospheric leakage into space is part of the reason it is now dry.
It's worth noting that Voyager 2 only had about 60 seconds to experience the plasmoid as it whizzed by Uranus.