Hayden Mackenzie, of Ardgowan School, asks :-

How high will you have to be to begin floating around in space?

Robert Evans, an amateur astronomer and a physics teacher at Southland Boys' High School, responded.

You would have to be a long way from Earth, even further away than the moon which is nearly half a million kilometres distant, to float in space. Any closer and you would be gradually pulled towards the Earth by its gravity, moving faster and faster until you sped through the atmosphere as a meteor.

However, there is another way that you can feel as though you are floating in space: like the astronauts in the space shuttle and the Cosmonauts in the Mir space station. This is called "free fall". In this case you need go only 200km up: just high enough to get out of the Earth's atmosphere. But you have to be moving very fast in orbit around the Earth. Anything that is moving in an orbit, like the satellites that you can sometimes see moving across the night sky, is actually falling freely towards the Earth but, since it is moving very fast sideways, by the time it would have reached the Earth the Earth's shape has curved away from it. This situation continues right around the Earth, and so the object just keeps moving. Since there is no air up there, you have no sensation of moving, and so you feel as though you are floating in space.