Earth doesn’t take 24 hours to rotate on its axis!

It’s actually 23 hours, 56 minutes and 4 seconds. This is the amount of time it takes for the Earth to completely rotate around its axis; astronomers call this a sidereal day. Now wait a second, that means a day is 4 minutes shorter than we think it is. You’d think that time would add up, day by day, and within a few months, day would be night, and night would be day.

The Earth is the densest planet in the Solar System.

This varies according to the part of the planet; for example, the metallic core is denser than the crust. The average density of the Earth is approximately 5.52 grams per cubic centimetre.

Check out this cool graphic comparing the size of the earth to the moon.