Ask A Scientist© Astronomy Archive

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

Response #:  1 of 2
Author:      samuel p bowen
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 original 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.  



Response #:  2 of 2
Author:      asmith
Jupiter is so much bigger than the other planets that I think adding up all
8 others does not amount to a very large fraction of Jupiter's mass.  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      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 300 times bigger
than Jupiter.  The Sun is pretty big!