IASC: international asteroid search in telescope data, free for teams

For anyone, including school clubs and teams from different countries (no age limits are stated on the page): the International Astronomical Search Collaboration is a citizen science programme that provides high-quality astronomical data at no cost so that participants can make original discoveries. The main format is month-long asteroid search campaigns in which teams look for moving objects in image sets using the Astrometrica software (Windows only); the page lists current campaigns, for example the International Asteroid Search Campaign (168 teams). To take part, participants fill out the registration form and email it to IASC (a reply comes in 5-7 business days), then practise on practice image sets; a week before a campaign starts, an email with details arrives.