Some Facts About Light

1. Light is the fastest-moving stuff in the Universe. It travels an astonishing 300,000km per second. That's around 186000 miles per second.

2. Traveling at the speed of light, you can circle the Earth's equator in about 8 seconds

3. Due to the vastness of the Universe (it is constantly expanding), distance is measured in light-years and AUs. A light-year is the distance light travels in a year. An AU is the Astronomical Unit, which is the distance between the Earth and the Sun.

4. A light-year is the distance light covers in a year. There are about 3 billion seconds in a year. Light travels 300 million meters in a second. So in a year, light travels about 9 trillion kilometers. That is around 6 trillion miles. If two objects are 10 light-years apart, that is 90 trillion kilometers. Huuuuge

5. One AU is the distance between the Earth and the Sun. That's roughly 150 million kilometers. So if two objects in space are 3 AUs apart, that is 450 million kilometers.

6. It takes 8 minutes for light to reach us from the Sun. Takes about 1.3 seconds from the Moon

7. Some stars you see in the sky are 'dead' already. The light you see is from when the stars were still alive. Before the light could get to Earth, the stars had lived and 'died'. A star dies when the fuel in its core is used up.

8. The closest star after the Sun (The Sun is a star) is called Proxima Centauri. It is around 4.22 light-years away.