*artist's drawing

diameter: 863,040 miles = 1,392,000 km (about 218 times the Earth's) mass: about 1,990,000,000,000,000,000,000,000,000,000 kg temperature: 5780 K (surface) number of moons: all the planets! any rings? no

The Sun is about 73% hydrogen - that's most of it.  Of the rest, about 25% is helium.  This leaves about 2% that is stuff like carbon, nitrogen, oxygen, neon, magnesium, silicon, sulfur, iron and over 50 other things.  It's the hydrogen atoms running into each other that creates all the heat. The core is where the energy is created. It gets transported to the surface through the radiation zone, then through the convection zone.
 

This would be the most unpleasant place in the entire Solar System!  Actually, the word "unpleasant" is a major understatement! First of all, you'd burn up immediately... But, if you were able to survive in some sort of magic, super-cooled space ship, there's no surface to land on. You'd just keep sinking in to the center where the temperature is about 15,500,000 K! Whew, that's HOT! Could you try to swim? Check out how much you would weigh on the Sun and then answer!

To escape the Sun's gravity and get out into space, a rocket would have to travel at a speed of 1,503,759 mph or 671 km/sec. That's about 23,135 times faster than your parents are allowed to drive on a U.S. highway! Right now, our fastest rockets can go up to 30,000 mph.

Let's put it this way: You're not leaving!  8-)

The Sun is a star. Stars are giant fire balls of gas. Of the parts of the Universe that we can see, it looks like there are about 100,000,000,000,000,000,000 stars... But that's just what we can see.

The Sun accounts for about 99.8% of the entire mass of the solar system... So, all the planets, moons and the asteroid belt put together are only about .2% of the "stuff" of our solar system. To put it a simpler way, if you cut a pizza up into 1000 equal pieces, the Sun would be a little more than 998 of the pieces and the rest of the planets and the asteroid belt would be a little less than 2 pieces! That's it!

The Sun's brightness is equal to 4 trillion trillion light bulbs! That's 4,000,000,000,000,000,000,000,000 of them!!

Sometimes, we can see little dark spots on the Sun called sunspots. Can you see some in our picture? An astronomer scientist named Galileo saw some way back in the year 1611. We think that sunspots are caused by big glitches in the Sun's magnetic field.  Have you ever played with a magnet? Well, lots of stars and planets are giant magnets!

Look up at our picture of the Sun... Do you see the big arch of fire shooting off the top right side? That's called a solar flare. These happen when the magnetic fields on the Sun's "surface" smack into each other. This causes giant amounts of gas to shoot out of the Sun. Sometimes they shoot up as high as 60,000 miles or 100,000 km and can last for hours! Solar flares are not dangerous to us, but they can really mess things up with a bunch of static when you are trying to listen to the radio. The only people right now who have to worry about solar flares are our astronauts. When they are floating out in space in their space ships, they have no protection against something called radiation that shoots out of the Sun during a solar flare.

Sun | Mercury | Venus | Earth | Our Moon | Mars | Jupiter | Saturn | Uranus | Neptune

Sources:
In Quest of the Universe, 2nd ed. by Karl F. Kuhn
Voyages Through the Universe, 2nd ed. by Fraknoi, Morrison and Wolff
Universe by Kaufmann
The Complete Idiot's Guide to Astronomy by Christopher De Pree and Alan Axelrod
The Astronomy Cafe by Sten Odenwald