BBC News Online: Sci/Tech

Solar eruption may flood Earth

The eruption, called a Coronal Mass Ejection, was spotted on Sunday by a spacecraft, the Solar and Heliospheric Observatory (Soho).

The burst of gas will enhance the solar wind, currently running at 685 kilometres per second, and produce a shock wave which could wash over the Earth.

If this occurs, then spectacular aurorae will be seen at higher latitudes.

The direction of CME is uncertain because the specific shape observed could be caused not just by an Earth-directed outburst, but also by the superposition of two or more smaller events, directed away from Earth.

The US National Oceanographic and Atmospheric Administration has forecast a 40% chance of some geomagnetic storm activity over Tuesday and Wednesday, with the chance at mid-latitudes being 30%.

Severe geomagnetic storm activity can affect power supplies on Earth and satellites in orbit.

The Sun's activity waxes and wanes over an 11-year cycle and this year the activity reaches its maximum.