Solar and Heliospheric Observatory

SOHO, the Solar & Heliospheric Observatory, is a project of international collaboration between ESA and NASA to study the Sun from its deep core to the outer corona and the solar wind.

SOHO was launched on December 2, 1995. The SOHO spacecraft was built in Europe by an industry team led by prime contractor Matra Marconi Space (now EADS Astrium) under overall management by ESA. The twelve instruments on board SOHO were provided by European and American scientists. Nine of the international instrument consortia are led by European Principal Investigators (PI’s), three by PI’s from the US. Large engineering teams and more than 200 co-investigators from many institutions supported the PI’s in the development of the instruments and in the preparation of their operations and data analysis. NASA was responsible for the launch and is now responsible for mission operations. Large radio dishes around the world which form NASA’s Deep Space Networkare used for data downlink and commanding. Mission control is based at Goddard Space Flight Center in Maryland.

Best of SOHO

Results for the SOHO Best 10 Images: 91,257 VOTES FROM 23,990 PARTICIPANTS, the first 10 images are the top 10 in order and the remaining 20 are the rest of the 30 selected from.

Click on an image below to view larger.

On-board Instruments

This is a list of links to in depth information about the on-board instruments, the teams that built and operate them and their scientific goals. See also the instrument resources pages for pointers about how to operate and analyse science data.

This is a list of links to in depth information about the on-board instruments, the teams that built and operate them and their scientific goals. See also the instrument resources pages for pointers about how to operate and analyse science data.

CDS (Coronal Diagnostic Spectrometer) CDS Rutherford Appleton Laboratory, United Kingdom
CELIAS (Charge, Element, and Isotope Analysis System) CELIAS Universitat Bern, in Switzerland
COSTEP (Comprehensive Suprathermal and Energetic Particle Analyzer) COSTEP University of Kiel, Germany (in German)
EIT (Extreme ultraviolet Imaging Telescope) EIT NASA/Goddard Space Flight Center, USA
ERNE (Energetic and Relativistic Nuclei and Electron experiment) ERNE University of Turku, Finland
GOLF (Global Oscillations at Low Frequencies) GOLF Institut d’Astrophysique Spatiale, France
LASCO (Large Angle and Spectrometric Coronagraph) LASCO Naval Research Laboratory, USA
  LASCO  Max Planck Institute for Solar System Research, Germany
MDI (Michelson Doppler Imager) MDI  Stanford University, USA
SUMER (Solar Ultraviolet Measurements of Emitted Radiation) SUMER Max Planck Institute for Solar System Research, Germany
SWAN (Solar Wind Anisotropies) SWAN FMI, Finland.
UVCS (Ultraviolet Coronagraph Spectrometer) UVCS Harvard-Smithsonian Center for Astrophysics, USA
VIRGO (Variability of Solar Irradiance and Gravity Oscillations) VIRGO Institut d’Astrophysique Spatiale, France

Dr. Joe Gurman of NASA’s Goddard Space Flight Center provides commentary on selected shots from SOHO’s 20 years in space.

After 20 years in space, ESA and NASA’s Solar and Heliospheric Observatory, or SOHO, is still going strong. Originally launched in 1995 to study the sun and its influence out to the very edges of the solar system, SOHO revolutionized this field of science, known as heliophysics, providing the basis for nearly 5,000 scientific papers. SOHO also found an unexpected role as the greatest comet hunter of all time—reaching 3,000 comet discoveries in September 2015.

When SOHO was launched on Dec. 2, 1995, the field of heliophysics looked very different than it does today. Questions about the interior of the sun, the origin of the constant outflow of material from the sun known as the solar wind, and the mysterious heating of the solar atmosphere were still unanswered. Twenty years later, not only do we have a much better idea about what powers the sun, but our entire understanding of how the sun behaves has changed.


In this video, Karl Battams of the Naval Research Lab talks us through a visualization of the comets that SOHO has witnessed.
Since its launch nearly 20 years ago, NASA and the European Space Agency’s Solar and Heliospheric Observatory has spotted 3000 comets. The mission’s The Large Angle and Spectrometric Coronagraph (LASCO) instrument blocks out the bright solar disk, making it easier to see the corona of plasma and dust around the Sun, normally only visible during solar eclipses. This instrument also provides a very large field of view of the region around the Sun.

This visualization utilizes SOHO data from 1998 – 2010 and shows over 2000 comets. Comets that were first observed by SOHO carry no labels, and comets witnessed by not discovered by the spacecraft are represented with their labels. Trails on the comets are color coded based on family: yellow – unaffiliated comets, red – Kreutz group, green – Meyer group, blue – Marsden, cyan – Kracht, and magenta – Kracht 2.