Today, NASA announced that the SOHO spacecraft has discovered it's 1000th comet! What is even more amazing is that the majority of these were discovered by amateurs, more or less looking for fun and the excitement of discovering a comet.
SOHO is a satellite jointly operated by the European Space Agency and NASA, launched for the purpose of monitoring the sun around the clock. One of the cameras, called "LASCO," uses a disk to block out the sun, allowing the faint tendrils of the solar corona (the sun's outermost atmosphere) to be seen (see picture below, courtesy the Jet Propulsion Laboratory).
Most of the comets are known as "sungrazers," or comets that approach extremely close to the sun. These comets are probably the pieces of a few large comets that broke up on a previous trip around the sun. Most of the SOHO comets are only a few yards (few meters) across, and they are completely destroyed after they pass the sun. This tells us that the comets are very loosely packed, and easily pulled apart.
Before SOHO, only a couple of dozen sungrazing comets were known, and now we know of over 1000! Congratulations to all of the people working with SOHO to find comets!