It's far more likely that a group hallucination took place than intelligent extra terrestrial life visited our planet. There have been multitudes of reports of shared group visions, and it may not be that you all saw the exact same thing. Sometimes it goes like this: You say to your friend, 'Did you see that?!', and your friend responds, 'Yeah!' Then, each person adds a little something of their own, 'it zigzagged', and another person, 'then it shot straight up in the air!' As you recall the experience, everyone's mind produces the collective memory as if they each actually saw the same thing. This process can be enhanced by ingesting mind altering substances. Memories aren't like a digital recording, we don't have a single area of the mind where our experiences are stored and recalled accurately every time, and memories can shift and change over time. After witnessing a crime, a dozen eye witnesses will recall details VERY differently (the gunman was tall, short, black, white, wearing a read jacket, wearing a blue jacket). The witnesses are all telling the truth of what they saw, but obviously they can't all be correct. It always amuses me getting together with old friends or at a family gathering where someone will say, 'remember the time...?' only to realize their recollection is slightly (or grossly) different than my own, and others present. I'm not saying this is exactly what happened in your situation, but I believe it's closer to the truth than the alien explanation. It's that Occam's razor thing again...