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Joined 2026-09-21 Message
Incoming links: Comet Facts by National Aeronautics and Space Administration
Comet Created 2026-10-05 Updated 2026-11-05
A comet is a small astronomical body containing volatile material and solid grains, capable of becoming active when heated. Its comet nucleus is the compact reservoir. As volatile ice undergoes sublimation, escaping gas carries dust outward and can make a diffuse cometary coma and a comet tail.[ref]
Comet Facts by National Aeronautics and Space Administration. Structure and activity: nucleus, heating, coma and the two tail components
A cometary dust tail responds strongly to radiation pressure, whereas ionized gas couples to the solar wind and magnetic fields. The visible tail is therefore not simply an exhaust trail opposite the direction of travel. An inactive distant comet can lack a prominent tail. Its Kepler orbit, later planetary scattering and material loss together determine the observable history.