Here is our incredible Solar System which has fascinated humans for all time:
In our Solar System, some planets orbit nearer the Sun than Earth, and some planets orbit further away from the Sun than Earth.
The time it takes for a planet to travel once around the Sun is called a year. Planets further away from the Sun have longer years because it takes longer to travel the distance. Have a think about that.
Planets spin at different speeds to the Earth, so their days are not all 24 hours. For example, Venus has a day that lasts 243 Earth days!
Does that mean that on Venus your birthday is always tomorrow?!
Let's have a look at our Solar System....