Falling without ever landing
What Is an Orbit?
An orbit is falling sideways fast enough that the ground curves away as quickly as you drop.
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Step 1 of 5
Satellites are not beyond gravity's reach.
Gravity at orbital height is nearly as strong as on the ground, so nothing up there has escaped its pull in any way.
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Step 2 of 5
Throw something faster and it lands further away.
A gently tossed ball lands close by. A harder throw carries it further, because it travels further sideways during its fall.
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Step 3 of 5
Earth's surface curves away as you fall.
Our planet is a ball, so the ground drops away beneath a moving object. Go fast enough sideways and it drops away as fast as you fall.
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Step 4 of 5
That speed is what an orbit actually is.
Reach about eight kilometres a second sideways and you keep missing the ground. That is all being in orbit means.
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Step 5 of 5
Weightlessness is just falling together.
Astronauts float because they and their station are falling at exactly the same rate, so nothing presses them against the floor.
The space station orbits at about 7.7 kilometres a second, circling the whole Earth roughly every 90 minutes.
The short version
An orbit is continuous falling with enough sideways speed that Earth's surface curves away as fast as you drop towards it.
Try it yourself
Spin a bucket of water in a vertical circle. The water keeps falling towards the ground yet never leaves the bucket.
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