Monday 28 November 2005: Ten year anniversary for Solar exploration

The world's flagship solar probe, the Solar and Heliospheric Observatory (SOHO), is celebrating ten years in space on 2 December. Scientists are gathering at CCLRC Rutherford Appleton Laboratory on the anniversary of the launch to celebrate the achievements of SOHO which has revolutionised our understanding of our star, the Sun, and its impacts on the Earth.

The 12 instruments on board SOHO probe the Sun's every detail. One, the Coronal Diagnostic Spectrometer (CDS), is led from the UK, another was partly built in the UK, and UK scientists are involved in the operations and research of all instruments. SOHO's instruments are monitoring the complex, violent solar atmosphere, the charged gases that the Sun expels into space and examining the solar interior.

"Never before have we had such a detailed view of a star. All life on Earth is dependent on the Sun's energy, and when the Sun ejects clouds into space which engulf the Earth it can have severe consequences for satellite systems, 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", said Professor Richard Harrison, from the CDS team.

"SOHO has provided us with a comprehensive, detailed examination of a star over an extended period, and has operated superbly during that time. The advances generated by this mission are incredible", commented Professor Len Culhane of the Mullard Space Science Laboratory.

The mission has revealed the true nature of the Sun's violent atmosphere as it flings clouds into space and as huge magnetic loops tie themselves in knots to generate solar flare explosions. Scientists have discovered that the solar atmosphere is riddled with Earth-sized explosions and occasional tornadoes and the mission has also revealed how the interior of the Sun rotates. SOHO has even discovered over 1000 comets as they pass close to the Sun - a world record. Sophisticated observations have allowed scientists to monitor the far-side of the Sun and instruments have enabled weather maps of the Sun's atmosphere - probing temperatures, densities, solar wind speeds and even what the Sun is made of, from a distance of 150 million km.

Professor Keith Mason, Chief Executive Officer of the Particle Physics and Astronomy Research Council, the main funder of the UK involvement in the mission, said "SOHO continues to be a stunning success and over its extended lifetime has provided the scientific community and the public with a wealth of data about the Sun. Its success is testamount to the expertise of the scientists and industrialists, in the US and Europe, including the UK, that have worked on its design and operation."

Notes for editors

• SOHO is a joint mission between the European Space Agency (ESA), of which the UK is a member, and NASA. It was launched on 2 December 1995 and arrived in Lagrangian Point L1 (where the Sun's gravitational force and the Earth's are in balance) in February 1996.

• The Coronal Diagnostic Spectrometer was built, and is operated by, a team led from Rutherford Appleton Laboratory and including the Mullard Space Science Laboratory, with operations run from a mission control facility at RAL, through the NASA Goddard Spaceflight Center. The LASCO instrument was led from the US Naval Research Laboratory and was partly built at the University of Birmingham. Science highlights from CDS over the past decade can be found at ../

• SOHO's celebration event will be held at the CCLRC Rutherford Appleton Laboratory on Friday 2 December. Several short talks describing the history and results from SOHO will start at 10.30am and the event finishes with lunch. Interviews and photo opportunities will also be available on the day. If you would like to attend please contact Natalie Bealing.

• The Council for the Central Laboratory of the Research Councils is one of eight UK research councils and is one of Europe's largest multidisciplinary research organisations supporting scientists and engineers across the world. It operates world-class large-scale research facilities, provides strategic advice to the government on their development and manages international research projects in support of a broad cross-section of the UK research community.

For more information please contact:

Natalie Bealing, RAL Public Relations Officer
 press@cclrc.ac.uk,  +44 (0) 1235 445484

Prof Richard Harrison, Head of Space Physics, CCLRC Rutherford Appleton Laboratory
 r.harrison@rl.ac.uk,  +44 (0) 1235 446884

or Professor Len Culhane
Mullard Space Science Laboratory, Holmbury St Mary, Surrey RH5 6NT
 jlc@mssl.ucl.ac.uk,  01483 204139