The Sun is about 1,392,000 kilometers or 875,000 miles across. If you wanted to put a belt on the sun to hold up its pants you would want to know its circumference and for that you just apply a little math. The circumference of a sphere is determined by multiplying 2 times pi (3.14) times r (the radius). If you know the diameter is 875,000 miles then you also know the radius (radius is just half the diameter). In this case, to determine the circumference of the Sun you must multiply 2 times 3.14 times 437500 which gives you a circumference of 2,747,500 miles. The Sun needs a pretty big belt to hold up its fireproof jeans!
How long would it take to drive around the Sun? At 60 miles per hour, it would take 45,791.6 hours to drive around the Sun once. That’s just shy of 1908 days or 5.22 years (not counting stops for gas at your local solar gas station)! If you were to walk around the Sun without ever stopping at a man’s average pace of 3.5 miles per hour it would take you 785,000 hours or 32,708 days or 89.6 years! If you insist on 8 hours of sleep a night, add another 29.8 years on to the trip.
But there’s more to the Sun than just how much space it occupies. Another consideration is how densely packed the material is in the Sun. Think of it this way - If there were a balloon shaped exactly like you and inflated so it was just as tall and wide as you are, would it still be as “big” as you? Technically, yes. It would occupy the same amount of space. But it wouldn’t weigh nearly as much or contain as many atoms. It wouldn’t have the same mass as you. But a block of lead carved to exactly your shape would actually have MORE mass than you do. The atoms in the lead are more densely packed than the atoms in your body.
Remember from our previous post - What is the Sun and what is it made of - that the Sun is made up of some of the lightest stuff there is - Hydrogen and Helium. Together, these two elements make up about 98% of the entire Sun and individually these elements are so light that they weigh less than air and will float if you fill up a balloon with them. But the Sun is so large, has so much Hydrogen and Helium and is so densely packed together with the stuff that its mass comprises more than 98% of all the mass in our solar system. If you took all the planets, all the moons, all the asteroids and comets and dust and gas and squeezed it all into a ball, it would equal less than 2% of all the mass in the solar system and the Sun would make up the remaining 98%!
April 28th, 2008 at 12:17 pm
[...] considered answering this in my previous post - How big is the Sun - but found the question so well answered elsewhere that I’ll give it its own post. The short [...]