Recovering of comet Catalina with the Schmidt telescope
Solar System objects like asteroids and comets appear like moving targets in the stellar fields observed with telescopes. Observations spread over various nights allow us to compute accurately their orbits. Comets, in particular, can present elongated (elliptic), periodic orbits, like the famous comet Halley, passing close to the Earth every 76 years or so, and visible to the naked eye (the last time in 1986, but it was probably observed since prehistoric times). |