Ask A Scientist© Astronomy Archive

Question:  The sixth graders at Lester School in Downers Grove would like to ask 
a question about the sun and the earth.  How many times bigger is the sun
compared to the earth?  We are studying about why we have seasons in the
temperate zones (middle latitudes).  Thank you for answering our question.
lester e school

Answer:  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 (109)^3, or over 1,295,00 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.
Whoops! Just re-read my response. I'm sure you recognized that I meant to type
1,295,000 .
Rcwinther