Book 8, Question 120
Why Do Comets Have Nuclei That Look Dark and Lumpy?
Comet nuclei look dark and lumpy because they are dusty, rocky ices shaped by jets and time! Close-up photos from spacecraft show that they are not shiny ice cubes at all. A dirty snowball can look more like a charcoal space potato!
More fun facts
- A comet's nucleus is mostly ice coated with dark organic material.
- The surface of a comet's nucleus is often dry, dusty, rocky and dark.
- Photos from close flybys show jets of dust and a rough, bumpy surface on comet nuclei.
- NASA's Deep Space 1 flew past comet Borrelly in 2001. Its nucleus is about 5 miles (8 kilometers) long.
- The Hubble Space Telescope saw two jets shooting out of the nucleus of Comet Siding Spring in opposite directions.
- Since the 1980s, several spacecraft have studied comets up close.
Sources: NASA Science, NASA, NASA Space Place
Questions kids ask
If comets are made of ice, why are they dark?
The ice is covered by a coat of dark dust and organic material, a bit like dirty snow.