Senior Nasa scientists have warned of the problems that a once-in-a-generation "space storm" could pose to Britain. Here a British space scientist, Dr Chris Davis, explains why this has occurred and what is being done about it.
By Dr Chris Davis, Space scientist at the Rutherford Appleton Laboratory
Published: 9:00AM BST 18 Jun 2010
"Look at images of the Sun taken from space and you will see that it is not the plain yellow disk that we see shining through the clouds on Earth.
Spacecraft images reveal the Sun as a rotating, seething fiery ball of electrically charged fluid. Magnetic fields generated by this constant churning drive the activity cycle of the Sun.
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Complex tangles of high-intensity magnetic field are created from which violent eruptions of material can occur. Each one of these solar storms is a magnetic bubble containing around a billion tonnes of material from the hot solar atmosphere travelling at a million miles an hour.
The more tangled the Sun’s magnetic field, the more frequent these eruptions become, with the number of outbursts reaching a crescendo every eleven years or so.
When a solar storm is launched into space, the material accelerated with it represents a hazard to space-borne electronics and astronauts.
Sitting on a ball of rock some 93 million miles from this cosmic popcorn machine, we have an interest in knowing when such a storm is heading towards us and what the consequences will be when one arrives.
The most beautiful manifestation is the aurora (the northern and southern lights), created when hot solar particles enter the Earth’s protective magnetic bubble and energise the atmosphere high above the north and south poles.
As these charged particles flow through the Earth’s ionosphere (an electrified layer in the Earth’s upper atmosphere), they can induce surges within the world’s power grids that can damage vital transformers.
As we head towards the next peak in solar activity in 2013, researchers at Lancaster University are developing computer models to investigate the effects of such currents on our national grid system.
The energy dumped into the upper atmosphere during such a storm can also temporarily distort and weaken the earth’s ionosphere, disrupting radio communications and reducing the accuracy of civilian GPS navigation systems.
The speed, intensity and frequency of these solar storms is very variable and predicting their occurrence is the holy grail of solar science. Missions such as the two Nasa STEREO spacecraft are doing much to advance our understanding.
Viewing the Sun from positions either side of the Earth, these spacecraft have made the first 3D images of the Sun, allowing complex changes in the Sun’s magnetic field to be studied in great detail prior to the eruption of a solar storm.
The STEREO mission also carries two UK-built cameras that image the space between the Sun and the Earth so that Earth-directed storms can be tracked all the way to our planet.
At the Science and Technology Facilities Council's Rutherford Appleton Laboratory in Oxfordshire, researchers are working with government forecasters in the USA to improve predictions of a storm’s arrival at Earth.
Given enough warning, satellite operators can hibernate sensitive electronics, power companies can prepare for surges and astronauts reschedule spacewalks.
With over 100,000 images collected from the UK cameras so far, keeping up with the Sun’s tantrums is a full-time job.
As a result, the UK STEREO team have joined forces with the Royal Observatory, Greenwich and the Galaxy Zoo team to create "solar stormwatch" where member of the public can assist this pioneering research by identifying and tracking storms in STEREO images.
Some may even help predict the arrival of the next solar storm at Earth.
The Sun produces a "perfect storm" at Earth once per century.
An event in 1859 caused major disruptions to the US telegraph system. In 1989 a solar storm caused the power-grid in Quebec to fail.
As we become dependent on satellite technology we will need a reliable space weather forecast."
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