Key facts
- Category
- Comets
- Object class
- Comet nucleus
- Mass
- ~220 billion metric tons
- Scale fact
- 11 kmmean diameter
- Estimated age
- ~4.5 billion years
- Composition
- Water ice, dust, frozen volatiles
Halley's Comet
11 kmmean diameter
Details
Halley's Comet nucleus is the solid core of the best-known periodic comet. ESA’s Giotto mission found that its dark surface reflects only a few percent of incoming light and that jets emerge from localized active regions rather than the whole nucleus.
Edmond Halley used earlier observations and Newtonian mechanics to predict the comet’s return, correctly linking separate apparitions to one orbiting body. Its roughly 76-year period made a comet predictable rather than a one-time event.
During the 1986 return, Giotto passed about 600 kilometers from the nucleus. The images revealed an irregular, very dark body whose bright coma was fed by jets from limited areas. The object measured here is that nucleus, not the much larger cloud and tail visible from Earth.
Links
- Preset views
- Wikipedia
- Halley's Comet on Wikipedia
- Universe journey
- Solar System
Size neighbors
Objects near Halley's Comet on the scale
On the logarithmic size axis, Halley's Comet falls between 52246 Donaldjohanson and Deimos. The band uses nearby Comet nucleus records.
Shared physical scale
8.41km
Sources
References for Halley's Comet
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Halley's Comet — Wikipedia
- Visual reference: Wikimedia Commons (Vega 2 1986 / Russian Academy of Sciences, Public domain)
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About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.