Earth & Space
Why do satellites stay in orbit?
A satellite falls yet stays in space. Flauschi traces its orbit with Puschel.
The short answer
Earth's gravity pulls a satellite inward while it moves quickly sideways. With the right combination, it keeps falling around Earth instead of hitting the ground. Being in orbit does not mean gravity has disappeared.
An imagined Wusel scene
Puschel and Flauschi investigate
Puschel draws only a downward arrow and makes his paper satellite crash. Flauschi adds its sideways motion. Together they draw a curved path around Earth. Their picture still keeps the arrow pointing towards Earth.
Try explaining it
Which two things together explain the orbit?
Choose a), b) or c), then explain your choice.
- a)Earth's pull and sideways motion.
- b)Pull towards Earth without sideways motion.
- c)Sideways motion without a pull towards Earth.
Show the explanation
Correct: a): Earth's pull and sideways motion.
Earth's gravity pulls a satellite inward while it moves quickly sideways. With the right combination, it keeps falling around Earth instead of hitting the ground. Being in orbit does not mean gravity has disappeared.
Word help
- orbit
- The path of one body around another.
- satellite
- A body orbiting a larger world, natural like the Moon or built by people.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
Gravity pulls inward
Earth attracts the satellite. Without this it would not follow the same curved orbit.
Sideways motion matters
It travels quickly sideways. On a suitable orbit it falls towards Earth while continually missing the ground as Earth curves away below.
Conditions must match
Height and speed are linked. Thin remaining air may slow low satellites, changing their orbits. A satellite is not too light for gravity.
Why falling and orbiting fit together
Without Earth’s attraction, a satellite in this simplified model would continue straight. Gravity keeps changing its direction inward. Suitable sideways motion makes an orbit. Straight-ahead motion and inward attraction work together; this does not mean an engine must fire continuously.
The key points again
Discovery 1
Gravity pulls a satellite towards Earth.
Source: [1]
Discovery 2
It also moves sideways. On a suitable orbit it continually falls around Earth rather than hitting the ground.
Source: [1]
Discovery 3
Altitude and speed must fit together. Drag and other influences can change an orbit.
Source: [2]