It just seems to me that it's entirely possible to pick up more, so why has it never happened?
2006-12-14 17:18:59 · 6 answers · asked by nameless 5 in Science & Mathematics ➔ Astronomy & Space
Luna, or the moon, was formed by a giant impact. It was not captured. Mars' moons, Phobos and Deimos, are thought to have been asteroids that were permanently caught by Mars' gravity. The Earth doesn't have any moons that were asteroids that have been permanently caught by gravity, but it HAS had some asteroids that were temporarily caught, and were therefore "moons" for a period of time.
In fact, we have one now: asteroid 2003 YN107 was caught by the earth's gravity in 1999 and is still orbiting. These types of asteroids are known as "corkscrew asteroids."
2006-12-15 02:50:45 · answer #1 · answered by Egghead 4 · 0⤊ 0⤋
I disagree with the previous 2 answers. The current accepted theory for the formation of he Moon is the "Giant Impact Theory." A Mars-sized planetoid crashed into the early Earth, separating some material from the proto-Earth into space. Gravity collected it into the Moon. Check out Wikipeia.org . BTW the Moon is actually moving away from the Earth a little bit each year. About 3.8 cm/year. A little hard to do if you are capturing it from space. Most of those moons end up ripping apart or crashing into the planet.
2006-12-15 02:00:59 · answer #2 · answered by phsgmo 2 · 1⤊ 0⤋
<>The Moon of Earth is believed to be an accretion satellite, meaning that minute particales, dust and loose material that came into range of Earth's gravity was collected into an increasingly larger ball until it became the moon we know today. So, any other such material would just be added to the existing mass. And, so far, no BIG hunk of stuff that could be captured by the pull of gravity and become a second moon has come into range.
2006-12-15 01:30:23 · answer #3 · answered by druid 7 · 0⤊ 0⤋
Moon was created by rotation of particles pulled by gravity while it revolves around the Earth. As it rotates, the greater gravity it makes that it captures more particles until it finally came on as what it looks in the present. No other things rotated the same way the moon did, so we now have only 1 moon.
When 1 planet has more moons, the gravity on it decreases. I think that the earth's gravity is enough to support life. So dont wish that stuff anymore. Thanks!
2006-12-15 01:40:56 · answer #4 · answered by Paw 3 · 0⤊ 0⤋
He's right, the Giant Impact theory is generaly accepted.
We speculate that the Moon must be formed mostly from Earth because their compisitions are so similar.
2006-12-15 04:16:10 · answer #5 · answered by socialdeevolution 4 · 0⤊ 0⤋
Capture of a satellite by a planet is an exceedingly rare event, if it can happen at all.
2006-12-15 01:55:23 · answer #6 · answered by Helmut 7 · 0⤊ 0⤋