View Full Version : Gravity on planets moons,asteroids?

2004-Jan-28, 06:54 AM
How much gravity is there on the surface of various planets, moons and asteroids? I mean rock-type planets such as Earth.

It would be especially interesting to see a chart showing a continuum of possible planetary sizes, masses and diameters.

2004-Jan-28, 05:26 PM
Moon's gravity is like 1/6 of Earth (Someone post before)
Mercury's gravity is like 1/3 of Earth
Venus's gravity is like 9/10 of Earth
Mars's gravity is like 3/10 of Earth
Asteriod's gravity ;) not so sure about it, but since they are small object, maybe 1/3 of the Gravity of Earth :lol:

http://seds.lpl.arizona.edu/nineplanets/ni...lanets.html#toc (http://seds.lpl.arizona.edu/nineplanets/nineplanets/nineplanets.html#toc)

Hope this help :(

2004-Jan-29, 08:31 AM
I think most asteroids are so small that they you couldn't feel any gravity if you were stood on them. In fact, I doubt you could stand on them; more just hover nearby particularly if they were rotating.

On a similar topic, when I was v. young I wrote a story about what would happen if the earth stopped rotating. I presumed that the lack of rotation would increase the effects of gravity hugely and we'd all end up squished. IIRC when my teacher took me through the maths of it, the effect would only just be detectable.

A bit like all the panic over the planets lining up, with predictions of tidal waves and earthquakes, all based on bad maths.

2004-Feb-02, 08:03 PM
Asteroids do have a little bit of gravity. Ceres, the largest one, has about 3/100 of Earth. A normal-sized one like Eros would have something like 1/1000 of Earth. I have about 1/100,000,000 of Earth if you "stood" on my stomach.

You can, in fact, stand on an asteroid. If it were spinning to fast, it would have probably torn itself to pieces already! It wouldn't really work to walk, though...

2004-Feb-04, 01:49 AM
Gravity is a direct result of mass. The higher the mass, the more wieght (gravity) you would feel.

You can stand on an asteroid. The NEAR spacecraft landed on one, and it was a couple of hundred kilos, at least.

Remember Newton? He proposed that all matter attracts all other matter, by an amount dependant on distance.

In a practical sense, it means that you could stand on an asteroid, but depending on its size, any movement (a step, or a jump) could result in you reaching terminal velocity--and viola, you would be in orbit! :blink:

2004-Feb-04, 06:40 AM
And remember you would be attracting the asteriod, so if the asteriod had a mass of 1000kg and you weighed 100kg there would be an effective mass of 1100kg.