| | SOHO factsheet
Staring at the Sun
Name SOHO stands for SOlar Heliospheric Observatory.
Description SOHO flies in a halo orbit around the Lagrangian point, L1. This point is about 1.5 million kilometres from the Earth towards the Sun. Data from SOHO will help us understand our daylight star. It is the only star we can observe in such detail and the star on which we all depend. Its science ranges from the Sun's hot interior, through its visible surface and stormy atmosphere, to distant regions where the wind from the Sun meets atoms coming from among the stars. SOHO is a joint ESA-NASA project.
Launch 2 December 1995 (NASA Atlas-IIAS rocket at Cape Canaveral, United States).
Status In operation.
Journey Due to a flawless launch, SOHO needed very little thruster fuel for course corrections during its journey to its operating position. This position is a point in space called 'Lagrange Point L1', 1.5 million kilometres from the Earth towards the Sun.
Note Discoveries from SOHO include complex currents of gas flowing beneath the visible surface, and rapid changes in the pattern of magnetic fields. It has made the largest and most detailed database of solar-surface features, as a base record for generations to come.
In June 1998, ground controllers lost contact with SOHO. Intense efforts to restore contact paid off six weeks later when the spacecraft responded to commands sent from ground stations.
Although not designed for the purpose, SOHO has become the most prolific discoverer of comets in the history of astronomy. On Monday 12 August 2002, about 16:05 UT, SOHO spotted its 500th comet as the comet passed close to the Sun.
One of SOHO's instruments, called LASCO, (Large Angle and Spectrometric Coronagraph) routinely monitors a huge region of space around the Sun, 24 hours a day. Most of SOHO's comets have simply flown unexpectedly into LASCO's field of view.
Two other instruments, SWAN and MDI, allow scientists to 'see' what is happening on the far side of the Sun.
Last update: 28 July 2003 | |
