Old gas blob from Uranus found in vintage Voyager 2 data
By Meghan Bartels March 26, 2020
An animation shows the strange magnetic field of Uranus. The yellow arrow points toward the sun and the dark blue arrow represents the planet’s axis.
(Image: © NASA/Scientific Visualization Studio/Tom Bridgman)
Buried inside data that NASA’s iconic Voyager 2 spacecraft gathered at Uranus more than 30 years ago is the signature of a massive bubble that may have stolen a blob of the planet’s gassy atmosphere.
That’s according to scientists who analyzed archived Voyager 2 observations of the magnetic field around Uranus. These measurements had been studied before, but only using a relatively coarse view. In the new research, scientists instead looked at those measurements every two seconds. That detail showed what had previously been missed: an abrupt zigzag in the magnetic field readings that lasted just one minute of the spacecraft’s 45-hour journey past Uranus.
The tiny wobble in the Voyager 2 data represents something much larger since the spacecraft was flying so fast. Specifically, the scientists behind the new research believe the zigzag marks a plasmoid, a type of structure that wasn’t understood particularly well at the time of the flyby in January 1986.