Ha ha,
"Whatever happened to aliens ?"
They took one look at us and got as far away as they could.
On a serious note the lights that people have seen in the past could be to do with the sun and it's sunspot cycle, the effects of this massive power on the earth is clearly seen as Auroras but the power could cause the "lights/ufo's" that do seem to be seen in "cycles", sorry about that george i couldn't resist an unproven theory:0)