Index / Space Objects / Comet
Space Objects
Comet
Dirty snowball · two tails when near the Sun
As a comet nears the Sun, ices sublime and push out a coma; solar radiation pressure curves the dust tail, while the solar wind strips charged ions into a second, straight blue tail that always points away from the Sun.
Key specifications
Nucleus
1 – 50 km
Composition
~50% water ice + dust
Short period
e.g. Halley 76 yr
Oort Cloud
2,000 – 100,000 AU
Sheet 010 · Plate 1 of 1 · 1:1 infographic
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