If an object the size of Earth were orbitting earth...?

[Dirtyfist]

what would the environmental affects on our planet be if we had an object of similar mass/density/size as the Earth orbitting around us instead of the moon? Also how would it affect out atmosphere/magnetosphere..etc?

[rowanwitch]

we'd get some pretty scary tides

[boxtops]

We might fall off.

[Count-A-Strong]

And earthquakes. I assume you mean at the same distance.

[rowanwitch]

likely to have more seismic activity and that means more volcanoes.... earth would possibly be much colder from the amount of extra gas/ash in the upper atmosphere slightly offset from the heat produced. unlikely there would be life as we know it but some primitive forms like the tubeworms and algae that survive near thermal vents

[LazyGun]

On the plus side - Just think of the spectacular sky views, and the fantastic surfing opportunities! :)

[R1Geezer]

we'd be orbiting around a common centre of gravity in space, tidally locked like Pluto and Charon.

[beso]

Yes we would be tidally locked so we would not get the big tides rowanwitch anticipated.

There would be huge and frequent eclipses.

[rowanwitch]

bit of a let down then true about the sunsets though...

[R1Geezer]

if the moon still orbited between us it would be very much like the Jovian moon IO.

[beso]

Wow R1Geezer. What a fascinating thought. The tidal heating would be enormous. Io would be tame by comparison.

Isn't it nice to know that somewhere in the universe that exact scenario is happening right now (if "right now" had a sensible meaning over that scope).

[yeannow]

Not entirely sure but wouldnt we just implode or maybe just eat ourselves alive.......ps hope this helps.

[beso]

We would be able to watch the volcanoes on the Moon. They would erupt hundreds of kilometers above the surface because of the low gravity.

Imagine the eruptions going on during the eclipses. I can imagine no greater spectacle.

[modeller]

Would we be orbiting it or would it be orbiting us. ? Even if it was possible our orbit around the sun and our whole solar system would change.
All the planets would have different orbits .