Space invaders
a huge bubble of hot and magnetically charged gas has been discovered that may damage satellites after reaching the Earth's atmosphere. The bubble in the form of a giant cloud travels towards the Earth with a speed of 14,48,100 km per hour. When it reaches the Earth, the bubble expands to a width of about 32.18 million km. The magnetic disturbances on the Sun lead to formation of such massive storms ( Discover , Vol 18, No 6).
In 1989, a same kind of storm had knocked out a power grid in Quebec, Canada. A fleet of three nasa satellites first detected the cloud that had burst out of the Sun. These satellites tracked the happenings on the Sun and then the movement of the cloud through space. Researchers were able to get the first coherent picture of how a magnetic cloud interacts with the Earth's magnetic field.
The new finding is based on the observations made by the Solar and Heliospheric Observatory ( soho) satellite. Scientists at the National Aeronautics and Space Administration ( nasa) have placed the satellite nearly 14,50,000 km away from the Earth.
The soho satellite keeps an eye on the activities of the Sun. Four days after the eruption, the satellite was the first to detect the cloud billowing past its position some 6,40,000 km from the Earth. Within half an hour, the cloud spread over the Earth. Normally, the Earth's magnetosphere