Could the Earth leave it’s orbit??


Okay, I have no idea how true this is, but I learned in middle/high school that with each orbit the moon gets further away from the earth and in a couple million years it might get so far away that the earth won’t even have a moon anymore. Which makes me wonder… how stable is Earth’s orbit? Like what’s keeping us from getting too far away and flying off into space? Or is there a possibility of that happening ever? I’m so curious

In: 4

Short of a massive celestial body hurtling through the center of the solar system, no. It takes energy to move an object in an orbit, and lots of it.

The Earth will be swallowed up by the expanding Sun long before anything like that happens and we will all be long dead at that time.

What keeps us flying off into space is…. the sun’s gravity. The sun has 330k times more mass than earth. If the sun were to suddenly disappear then all the planets go flying off in a straight line.

Even if a huge planet hit the earth, it might nudge the orbit a bit (if not just outright destroying the earth), but not enough to knock it out of the sun’s gravity.

As others have pointed out, as things stand the sun is expected to explode before the Earth has a chance to leave it’s natural orbit. That doesn’t mean it can’t leave it’s orbit before then. It would just take an outside force.

A large body like a planet, a star, or even a black hole could in theory pass by us so close that it’s gravity knocks us out of our current orbit. At which point the Earth could become a [rouge planet](

As unlikely as this is, this is believed to be how Uranus became a part of our solar system. When you rewind our planet’s current orbits knowing what we do about physics far back enough, they start to no longer make sense. When you allow the computer model to have Uranus show up later and become captured by the sun’s gravity, they make more sense. That combined with it’s unusual axis tilt, and it’s moon’s orbits, it seems likely it started off as a rouge planet.

>with each orbit the moon gets further away from the earth

This is true. Because the Earth rotates faster than the Moon orbits the Earth, the Earth is slowly transferring its rotational energy to the Moon, causing the Earth to slow down and the Moon to orbit faster, very gradually boosting it to a higher and higher orbit.

>and in a couple million years it might get so far away that the earth won’t even have a moon anymore.

This is not true. The Earth does not have enough rotational energy to eject the Moon from orbit. As the Moon gets farther away and the Earth slows down, the rate of energy transfer will slow. Once the Earth is spinning so slowly that it matches the speed of the Moon’s orbit, the energy transfer will stop completely and the Moon will stop moving away. This process will take around fifty *billion* years, ten times longer than the Earth and Moon have existed.

The Earth and Moon have such a large “tidal” interaction because of their relative size and proximity: the Moon has about 1% of the Earth’s mass and is only about thirty Earth-diameters away. On the other hand, the Earth only has 0.0003% of the Sun’s mass and is 107 solar diameters away. The tidal forces accelerating the Earth are negligibly small, and the Sun will kill the Earth in other ways long, *long* before it has a chance to accelerate the Earth’s orbit by any significant amount.