The Solar and Heliospheric Observatory (SOHO) 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 is the most successful comet discoverer in history, having found more than one thousand eight-hundred comets in more than thirteen years of operation. The majority of these comets have been found by amateur astronomers and enthusiasts from all over the world, scouring the images for a likely comet candidate from the comfort of their own home.

To participate in SOHO Comet Hunting, citizen scientists need an Internet connection, photo-editing software and an understanding of what SOHO comets look like. For help with the last item in that list, a guide is available online. Citizen scientists need the ability to display gif images and find the pixel value of any given point in the images. If you don't have the software, you can use the java tool on the LASCO javagifs page to measure positions. Latest images and movies are also available from the LASCO site.

If you think your object is a comet, measure its positions, read the instructions on how to use the report form, and report your object.