 What is the connection between the aliens in the present holiday?
A gentle fancy for the Christmas Season—an oft-told tale with a wistful twistful of Something that left the Earth with a wing and a prayer. But this vast distance did not mean that isolation could endure forever. Instruments within the ship intercepted radio broadcasts and, within the hour, early TV signals. The history of the planet was tabulated as facts became available. They've had two world wars in one generation and that the third and final one is coming up you can't help feeling in everything they do." A meteor shower could pass over and their clumsy instruments could interpret it as an all-out enemy attack." They went much closer to Earth, not intending to commit themselves. Atmospheric analysis showed that as far away as we were."
 The aliens happen to fit the image many humans have of this holiday.
 The holiday allows the aliens to study the economic impact of holidays.  The timing of this trip allows the aliens to see an important holiday first hand.  The aliens happen to fit the image many humans have of this holiday.  The holiday means that there are more people off of work to interact with for the aliens to learn from.