> I can't believe that students made this.

Why not? Why are you prepared to believe anything else? Which is the more likely, students or aliens? You are prepared to discount students, but how do you know that aliens are any more motivated? They might just sit around in their spaceships all day smoking joints and drinking beer for all you know, happy to take the credit for all the students hard work. ;o)

Not all students fit your stereotype and if you want any confirmation of their inginuity you only have to look at some of their rag week pranks. Crop circles are easy to make and cause instant dismay amongst those who see them as supernatural. This is manna from heaven for pranksters.

When I was a student, we had a notification from the Principal that the Police were offering an amnesty for the return of road signs, etc. that were popular room decorations at the time. They said that they would turn up on Sunday morning to collect any items with no questions asked. This was seen as a direct invitation to "go collecting" on Saturday night. When the Police (7cwt) van turned up on Sunday, the exterior of the college was decked out from ground to roof with road signs, barriers, bunting, lamps, ladders, spades, shovels, pickaxes, there were two JCB's and a couple of dumpers, several cement mixers, numerous other items of plant and machinery. I mean it was totally irresponsible of us, but what a hoot to see the reaction of the coppers in the van.

My point is that when there's a motivation, especially if it's to have a good laugh, students will rally to the cause.