1
vote
2answers
124 views

Why not shoot a marble sized spacecraft at the moon?

I was thinking about the Google XPrize for Space Travel the other day. In order to claim the prize of building a robot that goes to the moon, travels 500m, and relays data, I had the idea of building ...
-1
votes
3answers
175 views

If an object fell from the moon [duplicate]

Ignoring the moons gravity, if an object sitting still (relative to the Earth, i.e. not in orbit) was dropped from the moon. How long would it take to hit the Earth?
1
vote
3answers
741 views

Speed of the Moon

Why the motion of the Moon looks very slow in the sky? Doesn't it need the high speed in order to escape the earth's gravity?
2
votes
2answers
107 views

Re: recoil (bounce) of objects under varying gravitational forces

First, I don't have a strong knowledge of physics, so please forgive my lack of precision in defining my question. Consider an airless free-fall situation where a steel ball and a balsa ball (with ...
2
votes
2answers
1k views

How does earth carry moon with it, if it can not force moon to touch it by gravitational force?

earth's gravitational force is acting on its moon in such a way that it forces moon to rotate round its orbit by centripetal force and carries it while rotating round the sun by gravitational force. I ...
5
votes
1answer
534 views

If the Moon had gravity as good as the Earth and a magnetic field could it have supported life?

If the Moon had gravity as good as Earth and a magnetic field could it have supported life? Because if the Moon had gravity, it could have retained water more than is present today on the surface. ...
2
votes
3answers
381 views

The theory of moon creation when a Mars size planet hit Earth

As we know the predominant theory where does the moon come from is that a Mars size planet hit the earth and took a chunk out of it which eventually materialized into moon. My question is that if a ...
5
votes
1answer
277 views

Determining Average Tidal Effects

Maximum tidal heights vary widely across the globe, from 16 m in the Bay of Fundy to mere centimeters elsewhere. These variations are due to coastline and shoreline differences. This makes it ...