Earth's Orbit and Rotation

An orbit is the path an object follows as it moves around another one. Earth moves in a circle around the sun once every 365.25 days. We call that path Earth's orbit.

The action of the earth turning or spinning around its center. If you stand in one place

Our solar system is made up of the sun, 8 planets and their moons. The planets all orbit around the sun and moons orbit around a planet.

A dark shape made when an object blocks light. When you stand outside, your body blocks sunlight and that makes a shadow.

A tool that provides evidence that the earth is rotating. It is made of a heavy weight

A group of stars that form a recognizable shape such as the big dipper. Today there are about 90 constellations

An ancient model of the solar system which we know today is not correct. It puts earth at the center of the solar system and says that everything orbits around the earth. "Geo" means earth and "centric" means in the center. Today we know that the earth orbits around the sun.

A model of the solar system which puts the Sun at the center and says that the planets orbit around the sun. "Helio" means relating to the sun and "centric" means in the center. Today we know that this model is correct.

The apparent shift of position of some stars through the year. This was not able to be explained by the Geocentric model which said that everything orbited the earth. The Heliocentric model was able to explain this illusion.

A year with one additional day added. We have leap years every 4 years because one orbit of the earth around the sun is 365.25 days. Our normal calendar has 365 days so every 4 years we have a leap year which adds an extra day.

An area on Earth that has a specific time that all people living there can set their clocks to. There are 24 different time zones.

An ancient tool used to tell time during the day. Part of it casts a shadow onto a flat surface marked in hours. It works due to Earth's rotation.