Do you need a telescope to discover a comet? These volunteers have another method.

SOHO was sent into space to study the Sun. Its instruments mask the central brightness in order to observe the neighboring regions. This technique also reveals small visitors who would otherwise go unnoticed: comets that have become bright near our star.

The images are accessible to participants from all over the world. Through the Sungrazer project, they can report the objects they find. In March 2024, a Hanjie Tan discovery brings the number of comets discovered in SOHO data to five thousand. A large part of this catalogue owes to the work of volunteers.

It is necessary to distinguish a suspicious point from a confirmed discovery: comparing the images and checking the trajectory remains essential. But the telescope does not need to be in the garden of the person who notices the object. An observatory built to monitor the Sun provides the views; elsewhere, a patient look may be the first to recognize a traveler who has slipped into it.