If you don't already know why a helium balloon tethered to the floor of a minivan has the power to make your jaw drop, you're going to want to see this. Seriously – set aside five minutes of your time, have a seat and watch. You won't regret it.
When you're looking for alien life, the best place to look is somewhere like Earth; the only place we know of that life exists. Kepler-186f, the first Earth-sized planet to be found in the habitable zone of a star, is the best bet we've ever found.