SOHO, so good as probe celebrates ten years in space

THE Sun is a boiling mass of "spaghetti-like" magnetic fields capable of causing explosions bigger even than planet Earth and creating giant tornados of fire.

Scientists have gained dramatic new insights into the true nature of the Sun over the ten years since the SOHO (Solar and Heliospheric Observatory) space-probe was launched.

The probe, which orbits the "balance point" where the gravitational pulls of the Sun and the Earth cancel each other out, was expected to last two years when it was launched.

But yesterday saw its tenth anniversary pass with no let-up in the stream of information being sent back to Earth. It has enabled physicists to monitor the far side of the Sun and create weather maps of the Sun's atmosphere from a distance of 150 million kilometres (approximately 93 million miles).

SOHO has taken amazing pictures of what appears to be a giant stationary tornado on the surface of the Sun, a pillar of fire spinning at 500,000kph.

Professor Richard Harrison, head of space physics at the Rutherford Appleton Laboratory in Oxfordshire, which is responsible for a sensor on SOHO, said: "Never before have we had such a detailed view of a star. When the Sun ejects clouds into space which engulf the Earth it can have severe consequences for satellites, navigation, communication and power distribution systems.

"We need to understand how the Sun works and how to predict how its activity impacts on the Earth."

One amazing feature of the Sun is that super-hot gases in its atmosphere can reach temperatures as high as 20 million degrees Celsius alongside other gases at the comparative cool of just 20,000C.

Prof Harrison said: "The reason has to be the magnetic fields. If you get the gases trapped in a magnetic field, it's protected, insulated, and the two temperatures can co-exist.

"The Sun is driven by magnetic fields. It's almost like a spaghetti of magnetic fields trapped on the surface of the Sun. It's weird."

Understanding how this works could help scientists build nuclear fusion reactors, which produce less radioactive waste than fission reactors.

"How you trap these gases, how you play games with them - this is exactly the sort of thing scientists trying to recreate as they look into nuclear fusion," Prof Harrison said.

SOHO has also provided a new understanding of massive solar flares which shower the Earth with potentially dangerous particles. Life on Earth is protected by the Earth's atmosphere, but the emissions can be harmful for astronauts caught on a spacewalk and to satellites.

"Flares are explosions where the magnetic fields have tied themselves in knots. They are like stressed elastic bands, they will give at some point," Prof Harrison said.

"That stressed energy has to get dumped into something. What it does is heat the gas around it and shoot it off into space."

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