How fast moon moving away from earth

Then again, it may have shed enough mass by that point that our orbit will expand and we will escape destruction. The Earth will be, at best, a scorched and chilled ball of rock. But hey, it will eventually get a really pretty set of Moon rings.

This question originally appeared on Quora - the place to gain and share knowledge, empowering people to learn from others and better understand the world. More questions:. This is a BETA experience. You may opt-out by clicking here. More From Forbes. May 6, , am EDT. Feb 9, , am EST. Feb 4, , am EST. Jan 26, , am EST. Computer simulations of such an impact are consistent with the Earth Moon system we see in the 21st Century.

The simulations also imply that at the time of its formation, the Moon sat much closer to the Earth - a mere 22,km 14, miles away, compared with the quarter of a million miles , km between the Earth and the Moon today. The Moon continues to spin away from the Earth, at the rate of 3. Without the Moon, the Earth could slow down enough to become unstable, but this would take billions of years and it may never happen at all.

The migration of the Moon away from the Earth is mainly due to the action of the Earth's tides. The Moon is kept in orbit by the gravitational force that the Earth exerts on it, but the Moon also exerts a gravitational force on our planet and this causes the movement of the Earth's oceans to form a tidal bulge.

Due to the rotation of the Earth, this tidal bulge actually sits slightly ahead of the Moon. Some of the energy of the spinning Earth gets transferred to the tidal bulge via friction. This drives the bulge forward, keeping it ahead of the Moon. The tidal bulge feeds a small amount of energy into the Moon, pushing it into a higher orbit like the faster, outside lanes of a test track.

This phenomenon is similar to the experience one feels on a children's roundabout. The faster the roundabout spins the stronger the feeling of being slung outwards. But the energy gained as the Moon is pushed higher is balanced by a reduction in the energy of its motion - so an acceleration provided by the Earth's tides is actually slowing the Moon down.

While 3. On early Earth, when the Moon was newly formed, days were five hours long, but with the Moon's braking effect operating on the Earth for the last 4. His suspicions were finally confirmed in the s, when laser beams bounced off mirrors put on the Moon by US and Soviet missions showed that it is moving away at the rate of 3.

The resulting loss of angular momentum is compensated for by the Moon speeding up, and thus moving further away. At the current rate of recession, the Moon must have separated from the Earth just 1.