The plasmoid in the magnetosphere of Uranus spoke about the loss of the atmosphere in the distant past. This conclusion was made by scientists from the NASA Goddard Space Flight Center, having analyzed the data of the Voyager 2 apparatus more than 30 years ago. An article describing the study was published in the journal Geophysical Research Letters.
Voyager and Voyager 2 solar system research missions launched one week apart in 1977. Today they are the farthest artificial objects from the Earth. Now automatic interplanetary stations are located at a distance of about 22 billion km from the Earth – outside the heliosphere, but also inside the solar system.
It is not clear when these stations will leave the solar system. The specific structure of the system complicates the movement of the probes, since it is surrounded by a hypothetical giant cluster of comets that are under the influence of the gravity of the Sun – the Oort cloud.
In January 1986, Voyager 2 flew at a distance of 81,433 km from the surface of Uranus and collected data that made it possible to detect two new rings, 11 moons, on the planet and determine that the temperature on its surface is about 241℃.
An additional study of the data after 34 years made it possible to find another feature that scientists had not noticed before – the probe flew through a plasmoid, which probably deprived Uranus of the atmosphere in the distant past.
Unlike any other planet in the solar system, Uranus rotates almost perfectly on one side – like a pig on a spit – performing a coup once every 17 hours. The axis of the planet’s magnetic field is 60 degrees from this axis of rotation, so when the planet rotates, its magnetosphere – the space in which its magnetic field is located – sways from side to side. Scientists still do not know how to build a model of this process. So far it looks like this:
In a new attempt to do this, scientists compiled a model based on data collected by Voyager 2 magnetometers, which tracked the strength and direction of the magnetic field of Uranus as the device flew past the planet.
The analysis showed that in the magnetosphere of Uranus there is a plasmoid – a huge plasma bubble, the length of which is about 204 thousand km and the width is 400 thousand km. The object is filled with ionized hydrogen.
According to scientists, plasmoids are formed when planets gradually dump their atmosphere into space. Its existence proves that Uranus lost its atmosphere in the distant past.