2007-05-04 01:49:11 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
I've heard about a theory which tells that the Moon itself was a roaming asteroid (planetoid) captured by the Earth, and since then it has the tendency of slow departing. However tidal friction indeed can reduce its potential energy in the gravitational field of the Earth . I've asked because there are to many hypotheses, but nothing for sure : maybe I can get some help.
2007-05-04 07:07:08 · update #1
Tidal friction. The Moon's gravity pulls up a small bulge on the Earth; the tides are the fluid water in the oceans being effected more than the solid ground, but even the ground gets deformed some. This makes the shape of the Earth not exactly symmetrical. The mass of the bulges has gravity, which pulls on the Moon. Because the Earth rotates on its axis much faster than the Moon orbits Earth, and in the same direction, the bulges get dragged out ahead of the Moon a little by friction with the rest of the Earth. From that position a little ahead of the Moon, then their gravity pulls on the Moon in the direction that it is orbiting, causing it to speed up. And speeding up an object in orbit makes it orbit farther out. The energy to do this is being stolen from the rotational momentum of the Earth. So as angular momentum is transferred from the rotation of Earth to the orbit of the Moon, the Moon gets farther away and the Earth's day gets longer. But the effect is EXTREMELY small and it will take millions of years for the day to get noticeably longer or the Moon to get noticeably more distant.
2007-05-04 01:53:27 · answer #1 · answered by campbelp2002 7 · 4⤊ 2⤋
The moon is moving away from the earth because the creation of the moon is likely one of the last hits from the Great Bombardment. The great bombardment is a theory that the Earth was pelted over and over again by asteroids and meteors. Then a Mars-sized asteroid or comet smashed into the Earth. Obviously it devastated the Earth, but it did a whole lot more than that. It caused the Earth to tilt at 35.5 degrees, giving rise to the seasons. It also created a cloud of matter around the Earth that eventually coalesced into what eventually became the moon.
Thus the moon is drifting away from the Earth as a result of this impact about 4.5 Billion years ago.
2007-05-04 10:07:36 · answer #2 · answered by Tippy the Turtle 3 · 0⤊ 1⤋
don't worry its only a few centimetres a year.
2007-05-04 09:06:01 · answer #3 · answered by Anonymous · 0⤊ 0⤋