An 'ice dwarf' is a
planetary body that is larger than the
nucleus of a normal
comet and much icier than any
asteroid. They are believed to be up to a few hundred kilometers across, and they are found mostly in the
Oort Cloud and the
Kuiper Belt in very large numbers.
''Ice dwarf'' is not an official
IAU classification, and it overlaps with the more official ''
cubewano'' and ''
plutino'' classifications.
Alan Stern of the
Southwest Research Institute believes there may be trillions of ice dwarfs beyond
Neptune that we have never seen.
Stern says that the three outer planets show signs of collisions with ice dwarfs, 1000 to 2000 kilometers in diameter.
Uranus could have tipped off its axis by an ice dwarf, and
Triton, the largest
moon of
Neptune, may have hit an ice dwarf as well.
List of largest ice dwarfs
;Ice dwarfs larger than 2000 km in diameter
#
Triton (2707 km)
#
Eris (2400 km)
#
Pluto (2306 km)
External links
★
Encyclopedia of Astrobiology, Astronomy and Spaceflight (David Darling)
★
Astronomers struggle to define 'planet'