Ask A Scientist© Astronomy Archive

Question:  How much mass do all nine planets have?
carol a jackson

Answer 1:  This is not something that most scientists would remember since there 
is no clear pattern and principle for the amount of mass.  If you go look up any 
introductory physics or astronomy book in the library, you will find the masses
listed.  The amount of mass in the planets is presumably the mass in the origina l cloud around
our sun.  I suppose the most interesting question is how much smaller that cloud 
was compared to the mass of the sun.  Would you guess the cloud is as large as
10 percent of the mass of the sun?  Good hunting.
samuel p bowen

Answer 2:  Jupiter is so much bigger than the other planets that I think
adding up all 8 others doesn't amount to a very large fraction
of Jupiter's mass. Hmmm. Hey, I actually looked it up:

Mercury: 0.33 x 10^24 kg
Venus:   4.87 x 10^24 kg
Earth:   5.98 x 10^24 kg
Mars:    0.65 x 10^24 kg
Jupiter: 1900 x 10^24 kg
Saturn:   570 x 10^24 kg
Uranus     87 x 10^24 kg
Neptune:  100 x 10^24 kg
Pluto:    0.7 x 10^24 kg
Total: ~2700 x 10^24 kg
  The various satellites of the planets (including our moon) add in another 10
or so x 10^24 kg.

The mass of the sun is 4
         1.989 x 10^30 kg so all the planets add up to only just over 1/1000'th
the mass of the sun.
The rule of thumb I usually remember is that, in terms of volume,
Jupiter is about 1000 times bigger than Earth, and the sun is about
1000 times bigger than Jupiter. The sun's pretty big!
Asmith