The Solar System

Our Galaxy Is a spiral galaxy Like this

We Are in the Orion Arm

The Solar System This consists of the sun and everything that orbits it Planets and their moons Comets Asteroids Meteors Meteoroids meteorites

gravity All of these things are locked in orbit due to the sun’s gravity So… The sun moves around the center of the galaxy And all that other stuff moves around the sun

Calculating Gravity Gravitational force is an inverse proportion This means that the magnitude of the force decreases as the distance between objects increases Gravity depends on the masses of the two objects and the distance between them

The small stuff Meteoroids Meteors Meteorites Small chunks of rock and metal that float in space Meteors Small chunks of rock and metal that get caught in Earth’s gravity and burn up in the atmosphere Meteorites Same as above BUT impact on the surface of the planet

sizes These guys range in size from 100μm to 50m across One definition is anything “considerably smaller than an asteroid and considerably larger than an atom” kind of vague But then again what is an asteroid?

Asteroids Defined as something smaller than a planet but larger than a meteoroid So I guess that means something bigger than 50 m across but smaller than a planet There are some big boys out there

Comets Different than asteroids Comets are made of dust, ice, frozen carbon dioxide (dry ice), ammonia, and some organic compounds (think like molasses or motor oil) Comets can be quite huge They also have a corona which is like a glow around them

The Corona Since comets are partly dry ice, when they get close to the sun the dry ice starts to turn from solid to gas (sublimation) the gas is the corona As it moves away from the sun the corona goes away The comet’s tail is this gas. It will ALWAYS point away from the sun