Can we remove all traces of humanity?

No.

No.

Somehow hide not only ourselves, but the markings and detritus of thousands of years of civilization? How much notice do you think we’re going to have when the aliens do decide to show up?

@Darth_Algar For starter’s how long would it take for the damage of Earth to be removed? Also all metals placed back in flake/nugget form? Scattered equally among the planet?
I am assuming that we would have progressed to beyond needing a home planet. Or any planet at all?

@Darth_Algar That would complicate, or resolve, the evolution/creation beliefs. Of course we will have to plant fossils underground and refill the oil and natural gas reserves. So the next group gets a prestine planet to evolve with

No.

No. Minerals from the Earth sometimes need to be processed with other chemicals (such as soap and sodium cyanide) and minerals (such as borax.)

@Darth_Algar The aliens need not be more advanced than us, but rather our descendents. So as to have the same starting position that we had.

Back to square one. While we travel the stars.

The World Without Us (2007) is a very interesting book that speculates on what would happen if humanity suddenly vaporized: how fast things would revert to wilderness, what would last and for how long, and how things would evolve from there.

It’s not quite the same as removing all traces—Mount Rushmore, for example, would probably be around for a long time—but it’s still quite a fascinating and plausible exploration of the aftermath of our extinction.

In theory, you could bombard the surface of the planet with so much energy, that the crust liquefies, and swallows everything into the mantle.
You would also have to retrieve all the human made artifacts from orbit, the moon, and mars.
Or you can just wait for Sol to engulf the planet when it turns into a red giant in a few billion years.

Not as long as we’re here..

The most complete way of erasing all trace of our presence would be to dump everything into a subduction zone and let it slide under the tectonic plate and into the earth’s mantle.

We can’t restore everything to the way it was. We can’t put the oil and the gas back into the ground so any new civilisation would have to use horse power and boats to get around.

@RedDeerGuy1

Regardless of how advanced we or these aliens are, how are we going to know they’re coming until they get here?

@Darth_Algar One can see a long way… in SPAAAAACE…

Of course, one can also pick up radio signals a long way, in SPAAAACE… and we’ve been broadcasting radio, TV, and even speciically SETI (Search or Extra-Terrestrial Intelligence) signals for over a century, and presumably any aliens who can get from star to star will have even more/better sensors than we do.

Even in an impossibly-dedicated/imaginative/united/insane/stupid/pointless effort to do something (say, as @ragingloli suggested, to liquefy the planetary surface with energy), not only would they have picked up our signals from before, but when they got here, the surface would look very peculiar and no doubt show telltale radioactivity not found elsewhere.

Maybe @RedDeerGuy1 ‘s earthlings will need to elevate their goal to never having existed, like a certain fictional alien culture in a classic sci fi story (by Asimov?). However in that story, the alien from that culture despairs of ever finding a way to accomplish that goal.

@Zaku

Yes, one can see a long way in space. However in this case you might as well be looking for specks of dust in a darkened room the size of a major metropolitan city. If we’re not specifically looking for it, and know where to look, chances are we’re not going to see it until it’s here. Remember how Oumuamua caught us by surprise a couple of years ago?

And sure, radio signals can travel a long way in space. But would we even know it if we picked up something from an alien civilization? And assuming they’ve figured out faster-than-light travel they’d arrive here long before their radio signals did.

True. If aliens are capable of traveling interstellar distances, they probably have some way to do it in a practical amount of time.

On the point of recognizing intelligent radio emissions, though, yes, I think SETI’s assumption that information signals would tend to have some sort of pattern that would tend to make them distinguishable from other radio radio emissions, makes sense.

And, if they are choosing to visit our star, out of the 100,000,000,000 stars in this galaxy, I expect it’s because they know there’s something interesting going on here. Probably, they mean to win Wimbledon!

But maybe we’ve already received all the signal we’re going to from them.