Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Lewis Thomson on 23/02/2022 10:32:18
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Geoffrey has asked for help finding answers to this question.
"In what ways does the earth loose mass? Like rocket launches which take objects off earth. Is there any effect on the earth like it's speed around the sun or is this too small to be measured."
Leave your answers in the comments below...
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Hi.
1. The single biggest factor that causes a loss of mass, is the loss of some gases from our atmosphere. Some molecules of gas have enough kinetic energy to escape from earths gravitational well. So the gas just drifts off into space.
1a. We also gain some gas. Some travels through space toward us and is captured in earths gravity. Planet earth isn't still, it's orbiting around the sun every year and everything is making an orbit around the centre of the galaxy, so we sweep out a lot of space and pick up quite a lot of gas as we do so.
2. We send off some rockets but that's not too important.
2a. We collect some bits of rocket that fall back to earth.
3. Some meteorites hit earth.
3a. OK, to be fair we don't usually throw stones up in the air so fast they escape into space.
4. Other stuff comes in.
4a. Usually similar stuff goes out.
That's the basic idea. A similar topic was discussed here: https://www.thenakedscientists.com/forum/index.php?topic=83942.0
Summary: Planet earth could be losing 50 000 tonnes of mass every year when you try and sum up all the loses and gains.
As a consequence, losing a few tonnes when rockets take off shouldn't matter too much. You would need to be talking about serious mining operations where thousands of tonnes of mass were regularly taken off the planet before it became a significant contribution. These sorts of mining operations have also been discussed before on this forum - I'm not sure where that thread has gone, sorry.
Summary: There's some interesting Newtonian mechanics to consider. In general the orbit of earth doesn't change just by removing mass. It might change if the space rockets were always taking off in the same direction all the time.
Best Wishes.