Ask A Scientist© Astronomy Archive

Author:      lester e school  and  ben
How many times bigger is the Sun compared to the Earth?

Response #:  1 of 2
Author:      rcwinther
Both the Sun and the Earth are almost perfect spheres; both bulge very
slightly at their equators.  The Sun's equatorial diameter is 1,391,400 km;
the Earth's equatorial diameter is 12,756 km.  So the Sun's diameter is
about 109 times that of the Earth.  If by "size" you mean volume, then the
Sun occupies about 10^3, or over 1,295,000 times the volume of the Earth. 
If you want to compare them by mass, the Sun has a mass of 1.99*10^30 kg,
and the Earth's mass is 5.98*10^24 kg, so the Sun is about 332,776 times as
massive as the Earth.  This is different from the ratio of their volumes
because the Earth has a larger average density than the Sun.



Response #:  2 of 2
Author:      hawley
The diameter of the Sun is 1,400,000 km, a little over 100 times the
diameter of the Earth; the volume of the Sun is, therefore, about 100 x 100
x 100 = 1,000,000 times the volume of the Earth (since volume is proportion-
al to diameter cubed).   So . . .  the answer depends on what you mean by
"big".