Ask a NASA astronomer! Why is there zero gravity in space?

Astronauts aren’t floating in space, they’re free falling—and so are you. Here's the amazing science behind so-called zero gravity.

When we launched our 'Ask an astronomer' series with NASA's Michelle Thaller, one set of questions stood out from hundreds, arriving by way of the curious and clever students at Courthill Infant School, Poole, in the south of England. Representing all the aspiring scientists in Dragonflies Class, Joshua, age 4, asked NASA's Michelle Thaller a brilliant question: "Why is there no gravity in space?" Here, Thaller explains the incredible science behind why astronauts appear to float in space, which is an interesting misconception fuelled by the term 'zero gravity'. (In fact, there is a small amount of gravity found everywhere in space, which is why microgravity is a more accurate term.) So what are they doing if not floating? They're actually constantly free falling, says Thaller, and so are you, the person beside you, and the entire planet Earth. It's a high-velocity orbit that allows astronauts to seemingly defy gravity, soaring so fast around the planet that they remain suspended instead of succumbing to Earth's gravitational pull. Michelle Thaller explains the very cool science of how orbits allow astronauts to seemingly defy gravity. You can follow Michelle Thaller on Twitter at @mlthaller.

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