Mission: Solar and Heliospheric Observatory
Mission type: Solar observations, space weather predictions
Launch date: December 1995
Launch vehicle: Atlas IIAS
Mission duration: 2 yr planned; 15+ elapsed
Orbit location: Earth-Sun L1 point
Status: ActiveOverview: The three main scientific objectives of
--Investigation of the outer layer of the Sun, which consists of
the chromosphere, transition region, and the corona.
--Making observations of solar wind and associated phenomena in
the vicinity of L1.
--Probing the interior structure of the Sun.
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SOHO Mission Profile
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Active region 10486 became the largest sunspot seen by SOHO, It
unleashed a spectacular show on 28 October 2003. An X 17.2 flare,
the second largest flare observed by SOHO and the third largest
ever recorded, blasted off a strong high energy proton event and a
fast-moving Coronal Mass Ejection. The spot occupied an area equal
to about 15 Earths, a size not seen since 1989. It later fired off
the largest X-ray flare recorded, on 4 November 2003.
Prominence of 09/14/1999
Emission in this spectral line (EIT 304Å) shows the upper
chromosphere at a temperature of about 60,000 degrees K. Every
feature in the image traces magnetic field structure. The hottest
areas appear almost white, while the darker red areas indicate
The three major interior zones are the core (the innermost part of
the Sun where energy is generated by nuclear reactions), the
radiative zone (where energy travels outward by radiation through
about 70% of the Sun), and the convection zone (in which convection
currents circulate the Sun's energy to the surface). The flare,
sunspots and photosphere, chromosphere, and the prominence are all
clipped from actual SOHO images of the Sun.
Solar System Simulator
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