I understand that orbits decay over time, is the Earth's orbit around the Sun decaying and what will happen?

Answer 1

Not all orbits decay.

Satellites in low orbit around the Earth have decaying orbits, because they are actually within the extremely tenuous outer layers of atmosphere. The ISS, for example, has to be boosted into a higher orbit every few months. But the Moon's orbit is actually getting larger, as it gains momentum from tidal forces.

Earth is too far from the Sun for either of those effects to change its orbit in any meaningful way. As far as we can tell, Earth's orbit is not decaying at all. The orbits of some asteroids are getting larger, because the solar wind and light pressure pushes outward against them. These effects are quite small, and for a planet the size of the earth, they are too small to have any significant effect.

Eventually, the Sun will expand into a red giant stage, and as that happens, the solar wind effect will get much greater, pushing the Earth farther outward. But this will not happen for billions of years.

Answer 2

Not all orbits decay. Satellites in low Earth orbit are not totally above the atmosphere. There are still enough gas molecules even 500 miles up to cause a small amount of drag on the fast moving satellite. That drag works against the orbital motion of the satellite, gradually lowering the orbit until it enters the denser lower atmosphere. That is why the space station has to be boosted a little every year to keep it at altitude. But satellites in higher orbits do not have that problem because they are really above all the atmosphere. That is why communication satellites in much higher orbits do not need to be re-boosted at all. And Earth does not have that problem in its orbit around the Sun.

Answer 3

Orbits of satellites in low-earth-orbit (LEO) decay because there is a small amount of gas from the atmosphere still present at those altitudes causing drag on those satellites. The drag causes them to slow down, thus dropping their altitude (decay).

There is no equivalent drag on the Earth in its orbit around the Sun. There are other mechanisms (mentioned above) that affect the orbit of the Earth but, these other effects are negligible compared with atmospheric drag on LEO orbiters around the Earth.

In an ideal solar system, once an orbit is set it should remain that way forever. Kepler and Newtons laws of motion still apply.

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Answer 4

Orbits remain constant unless there's another force acting on it. The orbits of satellites are affected by impacting fragments of our atmosphere, thereby slowing them down. In Earth's orbit about the sun, there's probably some impact as we run into meteors, but the effect is very, very small. And, we can be pummeled by the same number of meteors from the *back* side, actually causing our motion to speed up.

The Earth will likely remain orbiting until the sun runs out of fuel & expands to be a red giant - which will engulf us...

Answer 5

We determine the orbit change in term of the lenght of the days changes that the Earth Experiences.
As the Earth receives mass from the sun and the cosmos ,it increases. In order for the Earth to maintian rotational equilibrim it must increase its orbital time. And increase in orbital time means the average day on earth is getting longer and that is what has been observed.
If the orbital time increases the Earth's orbit increases proportionally.
I is true tha tthe Sun is losing mass in the form of radiation but this mass loss is compensated by the mass received by the Sun from the cosmos.

Answer 6

Earth is actually moving away from the sun because the sun is losing mass into space through its radiation and solar wind.

The angular momentum of the earth-moon system does not change by much due tidal forces by the sun which are small, but in any case, since the sun is rotating faster than we are moving around our orbit, this moves the earth OUT, not closer in, just like the orbit of the moon increases while the planet's rotation slows down.

But these changes are minute in comparison to orbital changes by the gravity of the other planets and irrelevant in comparison to the luminosity increase of the sun.

Answer 7

The Chinese have ancient records written by astrological observers. They recorded a planet, that they called Vulcan, breaking up and being devoured by the sun over the course of months. I wonder if the orbit of Mercury is decaying in the same way, considering it s small size and close proximity to the sun.

Answer 8

The sun will expand and swallow up our planet before we our orbit will decay. You only have about 4 billion years. Check out the life of a Red Giant.

Answer 9

Actually, the body to worry about is the MOON. It's orbit is slowly slowing down, and eventually, in many hundreds of millions of years hence, it will de-orbit and hit the earth. But that is so far in the future, that it's not worth worrying about. mankind has only been "around" for 1-2 million years in our bipedal form, so no telling what we'll look like that far in the future ( or be extinct by then ).
- The Gremlin Guy -

Answer 10

I'm not sure what you mean by "decay"

the main effect affecting orbits, is that tidal forces take away energy, and they take most of that energy away from the rotation not the revolution.

until the rotation and revolution periods coincide (like for our moon, and quite a few other bodies in the solar system).