Our image of Uranus has not advanced substantially beyond being the featureless blue ball captured by Voyager 2's instruments in 1986.
But last year, while reviewing NASA archives, two planetary scientists noticed something that previous analyzes had missed: a glitch in Uranus's magnetic field as the spacecraft passed through a type of magnetic bubble.
The new results, which appeared last summer in Geophysical Research Letters, reveals to us a much more fascinating Uranus than we thought. The flight of Voyager 2 was only able to detect this structure during 60 seconds of the 45 hours of data collection. It appeared as a very fast signal up and down in the magnetometer data.
Magnetic distortions
Gina DiBraccio and Daniel Gershman, from NASA's Goddard Space Flight Center, are two of these researchers. Motivated by the community's growing interest in the outermost planets, they spent hours manually processing thirty years' worth of data in a new way. And then they saw the plasmoid.
A plasmoid is a coherent plasma structure confined by a magnetic field. Plasmoids have been proposed as a natural explanation for globular lightning, magnetic bubbles in the magnetosphere, and other objects in comet tails, in the wind, in the solar atmosphere, or in the heliospheric current.
Scientists believe that a planet's magnetic fields can protect it, preventing the solar wind from destroying the atmosphere. However, these fields can also generate breakout options. This leads scientists to pay special attention to a planet's magnetic fields to understand how its atmosphere behaves. The magnetic burp that Voyager 2 went through was the first for Uranus.
It is quite similar to those observed on Saturn or Jupiter, but with a greater mass: this plasmoid formed a cylinder approximately 22,000 times larger than Earth: 204,000 kilometers long and 400,000 kilometers wide.
Scientists are particularly interested in studying plasmoids because these structures can extract charged particles from a planet's atmosphere and hurl them into space. If you change the atmosphere of a planet, you change the planet itself. More such discoveries could remain in the archives, awaiting further analysis.
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The news
Reviewing files, a plasmoid 22,000 times larger than Earth is discovered on Uranus
was originally published in
Xataka Science
by
Sergio Parra
.