Astronomers found flux ropes in Venus’s ionosphere (upper atmosphere), above the poles in the second week of January 2013. The flux ropes are magnetic entities stretching for hundreds of kilometers in size. Astronomers were boarding the European Space Agency’s Venus Express Spacecraft. Flux ropes have been seen before around other planets, including Earth. They transport superheated plasma gas from one end of the rope to the other.
Flux ropes are formed on Earth near the face of the planet opposite the Sun. The stream of charged particles known as the solar wind flows around the planet and thus a magnetotail of charged particles on the other side is created. Unlike most other planets in the Solar system, Venus has no magnetic field. The ionosphere (or upper atmosphere) of Venus acts as an obstacle to the solar wind.
The ionosphere of Venus remains unmagnetised most of the time, but when the solar wind reaches a higher pressure than the surrounding atmosphere it gets magnetised. In these conditions, relatively small flux ropes can form because of the higher speed of the solar wind blowing over the slower ionosphere.
In fact, the flux ropes on Venus form from solar particles on the side of the planet facing away from the Sun, in the magnetotail. Earlier, the giant flux ropes were also found in the atmosphere of Mars. Mars does not have a magnetic field like Venus.
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