So Large and So Small
4.5 Billion BC
-1004500 -1004500

NAT

RURAL MILKY WAY
	To send a spacecraft to the outer reaches of our solar system takes years, but a beam of light can cross the entire solar system in less than a day.
	To us the solar system is vast, but compared to our own galaxy, the Milky Way, it is microscopic, almost lost among the Milky Way's 100 billion other stars.  The beam of light that crosses our solar system in less than a day would take a hundred thousand years to cross the Milky Way.
	The solar system is composed of the sun and all the objects that travel around it: mainly planets, asteroids, and comets.
	Most important of these orbiting bodies are the planets.  From nearest the sun, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
	There have been different theories about how the solar system was formed, but today most scientists believe it was formed about 4.5 billion years ago out of a disc of hydrogen gas and heavier materials that slowly condensed into the sun and planets.