[Marc]

Marc asked the Naked Scientists:
   
I have been wondering about comets and the great distances they travel: 

Do comets get smaller and smaller as they travel through space - after all they are travelling millions of miles and are "giving off" material which make up their tails?

How come they are able to last as long as they do?

newbielink:http://www.thenakedscientists.com/HTML/podcasts/ [nonactive] - many thanks.

Marc

What do you think?

[Raghavendra]

No comets do not become smaller as they travel.. They have there own path after they are free from cosmic energy.

[lightarrow]

Thus, comets lose mass as they travel.

...unless an artificial probe crashes on it before sending data to an intelligent civilization... []

[flr]

They loose small amount of mass when they passes "near" planets and a bit more mass or get closer to Sun.

Apparently, they contains some small organic molecules (amino acids) and of course ice. It is possible that comets may seed planets with these small organic ingredient.

[yor_on]

Won't they pick up particles too as they move through Space? Not that it might make much of a difference perhaps, as most come from the Oort cloud.
 
'Life' & comets