Could alien artifacts not just be space junk?

Hi all,

Sorry if this sounds a boring explanation to all the "alien artifacts" we see here, but something you don't hear that often is that it could be space junk, bits of the huge amount of debris floating around in space.

Please excuse my lack of knowledge as far as this is concerned, but i figured if we can have space junk fall onto earth, and chunks of rock can hit planets, then couldn't a piece of metal floating around in space maybe hit a planet and stay there?

Like i said, i know little of how space works with gravity and all that, so maybe i'm just clutching at straws. Would space junk just keep floating in space and not touch a planet? If so, why do things fall to earth and not just stay up there?

It's just that whenever we see a new photo appear on this board, whether it's Mars, the moon or elsewhere, there seems to be only three possibile causes....

1. A rover left it there.

2. It's a rock formation.

3. It's an alien artifact.

Thanks in advance for any replies on this.

CX.

Is there anyone who has an opinion on this?

To clarify, i'm not posting it to debunk alleged alien artifacts, i'm genuinely interested if it is possible for space junk to float onto a planet and stay there?

I guess i'm kind of confused due to my very basic knowledge of the way space works. On the one hand you hear of stuff floating away in space forever, then again you do hear of things colliding with planets.

This could include manmade space junk no?

CX.

[edit on 13/2/09 by CX]

Would space junk just keep floating in space and not touch a planet? If so, why do things fall to earth and not just stay up there?

Eventually, many such objects encounter orbital decay as they are pulled into the atmosphere, encounter drag, and eventually plummet to Earth...all depends on their distance from the Earth and what type of orbit, etc.

Manmade satellites, etc. often use rockets to boost themselves into a higher orbit, as it starts to degrade, thus keeping them up longer and longer....

Could these artifacts be space junk? Sure, it's possible, they could also be terrestrial junk... Even testing proves little, as for all we know, the aliens use the same elements found here on Earth, so nothing remarkable about debris, unless it can be conclusively shown as being not of this world.

Thank you for that explanation.

It's nice to know that next time something mechanical looking is found in a pic of a planet, i have another option to think about.

CX.