Orbits
An orbit is the path an object in space travels around another. Lots of objects in the Universe orbit others. The Moon orbits the Earth.
Momentum
If an object is moving, it has momentum. This is what keeps an object moving in the same direction. The more momentum something has, the harder it is to change its direction or bring it to a stop.
Motion
Motion is when something moves from one place to another over time.
Everything around us is always moving, from tiny particles to huge galaxies.
In physics, we describe motion using ideas like distance, speed, and acceleration.
Measure a Day on Jupiter
Investigate Day and Night
On Earth, night follows day and day follows night. But why?
Complete this fun investigation to find out!
Measure the Sun's Rotation
Why Do Shadows Change Over Time?
Have you noticed that your shadow changes over time? The cartoon on this page shows why shadows change during the day.
How Do Satellites Stay In Orbit?
A satellite is an object which orbits another. An orbit is the curved path that an object in space takes around another object.
Explore Day and Night Around the World
Do different parts of the world experience day and night at the same time? Why do parts of the Earth have seasons? What are days and nights like at the north and south poles?