Wikipedia is the German name for a small tract of land on Mars, once thought to be inhabited by intelligent life but now known to be inhabited only by small, non-sapient, fuzzy creatures called Wikipedians.
In 2001, ancient texts in an unknown language were found just inches below the Martian soil in the Wikipedia region. In January of 2005, they were decoded by the team of dedicated epigraphic experts called GNAA, and were found to detail the history of an ancient civilisation inhabited by humans who called themselves "Mth#-V&kp!^^dy%" which sounds roughly like the English word "(somebody attempting rapid phlegm output)". It is presumed that these ancient people, whose technology was so advanced that not only did they have electricity and running water, but an Internet-like network called "hMth#-n^^!t", pirated U2 deluxe concert DVDs, telephones, and a sort of collection of all contemporary knowledge but which nobody really liked called "V&kp!^^dy&!-K*!^^th".
The texts also record the gradual demise of this society due to an infestation of the small, fuzzy, nonsapient creatures they called "Th&rp^^l!y" but which we know as Wikipedians.
These creatures covered the entire Martian food supply from the Sun, causing it to die, and were poisonous to humans when consumed. Eventually, as food reserves dwindled, the Martians attempted evacuations to their ancestral home on Earth, succeeding in relocating only 1% of the population (the rest stayed and died of starvation, asphyxia due to Wikipedians constricting around the airways, and broken necks and spines due to autofellatio).
For unknown reasons, there was a sudden decline in the population of Wikipedians, and their reproduction cycle slowed to a near-halt. At this point, there were still some 3.333 humans left. All but 33 of them were mauled to death by squirrels, and the remaining 33 sold the planet to nobody in particular for the modern equivalent of US$7.7BIL, and promptly left to start a civilisation in Antarctica.