The automated
solar probe SOHO (Solar and Heliospheric Observatory) was launched on Dec. 2, 1995, to study the Sun during
a relatively quiet period in the cycle of
solar activity. As it circled the first stable point in Earth's orbital path around the Sun (see three-body problem), its instruments
obtained the first images ever obtained of the extended outer corona, along with views of gigantic "tornadoes" near the solar poles. Contact with the satellite was temporarily lost in June 1998 but was successfully regained one month later. The SOHO program is being conducted jointly by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA); Japan is also taking part in this investigation into the physics of the Sun-Earth relationship.