• Question: why is there no gravity in space

    Asked by away130day on 28 Jan 2020.
    • Photo: Yuri Yushtein

      Yuri Yushtein answered on 28 Jan 2020:

      Actually, there is! All physical objects have a gravity field corresponding to their mass. Any passive object in free space would be affected by the gravity vector in point is space, and would basically move with the corresponding acceleration along this gravity vector. However, as in this state the object is practically in a “free fall” state, while having a mass, it will not have the weight (which is a force the object would exert on an obstacle preventing the free fall). So, as there is no weigh in the free fall situation, it is called weightlessness.
      If jump from something, while you are free falling, you are weightless, just like in space!

    • Photo: Abbie Hutty

      Abbie Hutty answered on 29 Jan 2020:

      Yuri has explained the detailed science very well already, but in simple terms every object has gravity, just how much gravity you feel from it depends on how big it is and how far away from you it is.

      So the Earth has quite a bit of gravity as it is quite big, and we are right on it so we feel it strongly. But up in space, even for spacecraft orbiting the Earth, they feel much less gravity as they are further away. But things in orbit, like satellites and space junk, all still fall towards the Earth because of Earth’s gravity – just very, very slowly. Most satellites would take years to fall back down to Earth.

      The moon has gravity too – not as much as the Earth as it is smaller, and we can’t feel it much from here on Earth as it is a long way away – but it is still enough to make the tides go up and down. But if you see the footage of people when they walked on the moon (so they are as close to the moon as we are to the Earth) you see they can take really big jumps as the gravity is less- but they still fall back to the ground as there is still some there.

      Even tiny things have some gravity – people have gravity, or individuals rocks, for example. You just can’t feel it as it is so weak.

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