Comet

1. Comet tails

1.1. Cause

1.1.1. Comets are passing from the Outer Solar System to the Inner Solar System.

1.1.1.1. Effect

1.1.1.1.1. The warmth of the Sun burns off any unstable material in comets

1.2. Cause

1.2.1. Comets are filled with ice, gases and dust.

1.2.1.1. Effect

1.2.1.1.1. They are sometimes called dirty snowballs

1.3. Cause

1.3.1. Comets orbit around the sun very fast.

1.3.1.1. Effect

1.3.1.1.1. It can take a few years.

2. Meteors

2.1. Cause

2.1.1. Small rock participles break off from the back of the comet.

2.1.1.1. Effect

2.1.1.1.1. These pieces of rock called meteors fall to Earth.

2.2. Cause

2.2.1. There is a clear night sky.

2.2.1.1. Effect

2.2.1.1.1. People can see comets and their tails