Space weather is caused mainly by storms and eruptions in our volatile Sun sending potentially dangerous radiation towards Earth.


It also causes the spectacular "aurora" light displays that have awed so many in the polar regions -- a beautiful show of radiation hitting Earth's magnetic field.

The Sun randomly and suddenly ejects bursts of its component plasma or magnetic matter in events called coronal mass ejections (CMEs), and is subject to equally arbitrary bursts of radiation called solar flares.

The life-giving star at the centre of our solar system emits radiation at temperatures of millions of degrees and constantly ejects charged particles and radiation that travels through space on solar wind.

Sudden flares or outbursts can cause geomagnetic storms that affect Manmade systems in space and on Earth, though the magnetosphere protects us humans from the worst effects on the ground.

CMEs, for example, can trigger magnetic current surges on long terrestrial lines like electric power lines.

The magnetic disturbances can also throw out radar and radio signals.

Out alone in space, satellites are easy targets.

Solar flares boost the level of radiation that reaches Earth and its atmosphere, which expands and becomes more dense for satellites to move through, causing drag that reduces their lifetime.

Satellites can also fall victim to sudden magnetic charge changes damaging their electronics.

There is a small risk for humans.

Some research says aircrew flying frequently at high altitude on long-haul flights may receive a radiation dose equivalent to several chest x-rays from exposure to solar flare radiation.

Astronauts, too may be in danger, hence extra-protective shields against radiation bursts that are provided in parts of the orbiting International Space Station.

Space weather is monitored by looking at the Sun with satellites and telescopes and measuring changes in the Earth's magnetic field and radio noise.

Even the aurora are monitored -- changes in their shape can indicate solar storm events.

(Data obtained from the European Space Agency)