Microrobotics: The Key to Extraterrestrial Life?

[ArmoredFairy698]

My younger sister and I were watching a show on the National Geographic channel this morning about extraterrestrial life. Here's what it had to say:

There have always been many suggestions as to if aliens really exist, and if they do, how they could travel to earth and survive our planet's atmosphere.

Some are now saying that perhaps microrobots are the key. These microrobots are so small that they have the ability to travel through space, (by whatever means -- even wormholes were presented as a possibility) and arrive at another planet with the ability to clone themselves and form colonies of millions of microbots.

So my question is, who built these microbots that came from somewhere else, and how can a machine clone itself that easily? Is this a technology that perhaps NASA is working with right now that could be a key to our colonialization of other planets?