Number Of Planets Date: Prior to 1993 How many known planets are
there, inside and outside the solar system? I have read in
Astronomy magazine that at least 2 planets were discovered
around a pulsar (I do not know where) and that perhaps a 10th
planet lies past Pluto. Any more I do not know about? I have not
heard of any good hard evidence for any planets other than the
usual nine. Update - March 2011 As 2011, there are officially
eight planets in our Solar System. Pluto, common thought of as
the ninth planet, is officially listed as a dwarf planet. There
are many dwaft planets in our solar system, Ceres, Pluto,
Haumea, Makemake, and Eris. There have also been planets
discovered outside of our solar system, thoughI do not have a
count on them at the present time. Click here to return to the
Astronomy Archives Update: June 2012