Gravity Gravity is a "pull"ÃÂ by all of the planets. All planets have a smaller planet or two circling around them, we have only one smaller planet circling us and we call this planet the Moon. Our moon pulls on the Earth giving the Earth a tilt. This tilt causes the Earth to have seasons such as spring, summer, fall, and winter. It also helps with the tides of our oceans. The Sun, of course, has the strongest pull of all. The Sun is the center of our solar system. Our solar system is called The Milky Way.
The Sun is a ball of hydrogen and helium gases along with other gases and metals that are constantly exploding. These constant explosions give off heat, which gives life to our planet. When the sun lets out these explosions, it throws out gases and metals, which are floating all over the place in outer space.
On dark nights in the Northern and Southern Hemispheres of the Earth, you can see some of these metals being pulled to the Earth by the Earth's gravitational pull. The magnetic attraction of the North and South poles start to gather up these particles of metals making them unite on the north and south poles. When these metals reach our Earths atmosphere they start to burn up. This is what causes the Aurora Borealis, otherwise known as The Northern Lights.