Asteroids in the infrared—Serendipitous observations with ISO

The infrared space observatory (ISO) observed many asteroids in great detail, including near-Earth asteroids (NEA). Additionally, a large number of observing programmes contain serendipitous observations of known and unknown solar system objects (SSO). The ISO specific constraints, like sensitivity, visibility and orbit parallax and their consequences for SSO extraction are presented. Model calculations demonstrate the efficiency and effectiveness of space-based infrared programmes for investigations of SSOs. Four large ISO programmes have been analysed and first results from the SSO search are discussed. The possibilities and limits of ISO with respect to near-Earth objects (NEO) are briefly mentioned.