Re:Was There a Civilization on Earth Before Humans?
by ianai on Saturday April 20, 2019 @03:51PM
(#19708518)
That’s my point though. The moon hasn’t degraded and crashed into the earth so it’s clearly possible for a satellite to orbit the earth indefinitely - for some suitable definition of indefinite.
Re:Was There a Civilization on Earth Before Humans?
by scottie_m on Saturday April 20, 2019 @04:28PM
(#19708701)
The moon’s orbit is taking it further from Earth over time, it it’s very far away and very massive, as well as being influenced by the Sun. A satellite’s mass is almost negligible, and compared to the Earth-Moon distance it’s distance from Earth is too. A pebble hitting the moon also isn’t going to do much to change its course, while the same pebble will do a lot more to a satellite. The same is true of dust.
Re:Was There a Civilization on Earth Before Humans?
by stouset on Saturday April 20, 2019 @05:37PM
(#19709013)
The moon has a ton of mass and—therefore—inertia. The chaotic effects of the system are still present, but require dramatically larger timescales to notice any kind of effect.
Re:Was There a Civilization on Earth Before Humans?
by gpm on Saturday April 20, 2019 @04:25PM
(#19708688)
The moon's stability is a good point, but not conclusive. The moon's orbit isn't perturbed by it's own gravity. It's also much larger, so much more mass (radius cubed)/surface area (radius squared), so less affected by solar wind, micro meteor impacts, and the like.
Over millions of years that will add up, honestly I'm hoping someone else will do the math/research and figure out if they add up to enough that they wouldn't still be orbiting earth.