• Question: what is the biggest comet in space?

    Asked by cheeseballs to Adam, Catherine, Karen, Leila, Nazim on 14 Mar 2012.
    • Photo: Karen Masters

      Karen Masters answered on 13 Mar 2012:

      Well I suppose you would stop calling an icy object a comet and start calling it a dwarf planet once it was heavy enough to make itself spherical. Light objects can be lumpy and irregular shapes, but things the size of planets are all spherical because their own gravity is so strong to make them so.

      You could do a calculation using information about the strength of ice to figure out how massive an icy body would have to be to become spherical, and I suppose just a bit less massive than that would be the answer to your question.

    • Photo: Adam Stevens

      Adam Stevens answered on 14 Mar 2012:

      Comets are different to asteroids in that they’re mostly ice. This means as they move they are continuously getting vapourised, which is actually the part of the comet we see.

      The biggest one is probably only about 20km across, whereas you can get asteroids hundreds of km across.

    • Photo: Leila Battison

      Leila Battison answered on 19 Mar 2012:

      The biggest one we’ve measured is the amazingly named Comet McNaught! (I think I will call my child this when I have one!)

      It was visible from earth in early 2007, and scientists measured the length of its tail, which is usualyl a good indicator of the size of the core. They found it was over 200 million miles long!

Comments