2006-08-17 03:43:56 · 11 answers · asked by heynowpauly 2 in Science & Mathematics ➔ Astronomy & Space
"supposedely" we sent up a scale and a one Kg weight. We had a robot to put the weight on the scale and radio back the value. That told us what the gravity was on the moon. … - ..- --. -- -..
Check out the story on Wiki.
2006-08-17 04:06:32 · answer #1 · answered by SPLATT 7 · 0⤊ 1⤋
We've known the effects of the moon's gravity on our tides for a couple of centuries. This together with the distance to the moon (which is done using paralax from earth) allowed us to find the mass and radius of the moon. That then allowed us to figure out what the acceleration due to gravity would be on the moon. This was known *long* before any craft were sent into space and could have been done by Newton (although I'm not sure he did, in fact, do so). In the same way, once we know the radius and mass of Pluto, we know how much the acceleration due to gravity would be there.
Of course, these old style techniques were improved upon when we actually did get some craft into space and were able to observe the effect of the moon on their orbits. Finally, one of the Apollo spacecraft did a 'fly-by' of the moon as a test of our equipment before the first actual landing.
2006-08-17 11:13:28 · answer #2 · answered by mathematician 7 · 2⤊ 0⤋
From the time taken by the moon to go around planet earth we could estimate it's mass
it's radius was also found by the time it took to cross the sun during an eclipse
Using these data in newton's laws of gravitation we knew the gravity on moon
2006-08-17 10:52:50 · answer #3 · answered by gadha 3 · 2⤊ 0⤋
The first astronauts who landed on the moon didn't say: "Oh, I feel 6-times lighter than home!". The scientists calculated it, but don't ask me how exactly - it is based on the Moon's mass and radius. But how they calculated Moon's mass is a different story. Probaby they used the time Moon needs to surround the Earth or something like that.
2006-08-17 10:54:40 · answer #4 · answered by Makra 2 · 0⤊ 0⤋
You get a rough idea by measuring it's diameter and assume it's made of similar stuff as is the Earth. If that assumption holds, the gravity on the surface of a planet is proportional to its radius.
A more reliable method is to measure its impact on other bodies, such as the Earth, meteorites and satellites.
2006-08-17 10:53:09 · answer #5 · answered by helene_thygesen 4 · 0⤊ 0⤋
All objects with mass have gravity. A principle in science states that the physical laws in the universe are unchanging. That is the basis of science, and is always been true.
2006-08-17 11:22:14 · answer #6 · answered by satanorsanta 3 · 1⤊ 0⤋
First, it was appoximated by guessing what the moon was made out of and estimating its volume. This can give you the mass of the moon from which gravigy can be derived.
Then, we sent probes that could measure it. The "fancy" measurement device consists of a known weight and a scale.
2006-08-17 10:53:33 · answer #7 · answered by selket 3 · 0⤊ 0⤋
Instead of repeating all the fact on the sites I posted, go to the links and you will see how it was all done. It is written in plain english and easy for even a 4th grader to follow (which is good for learning something new :) )
2006-08-17 14:40:52 · answer #8 · answered by Krynne 4 · 0⤊ 0⤋
Gravity can be determined by the size and density of an object.
2006-08-17 10:50:15 · answer #9 · answered by Wurm™ 6 · 1⤊ 0⤋
Because of its mass, everything with mass has gravity, everything including an atom.
2006-08-17 12:29:03 · answer #10 · answered by bprice215 5 · 0⤊ 0⤋