Astronomer Philip Plait is tired of radio personality Richard Hoagland's claims. He's had enough of Hoagland's assertions that NASA is covering up evidence of extraterrestrial life, that the infamous Face on Mars was built by sentient aliens and, of late, that otherworldly machine parts are embedded in the red planet's dirt.
And then there's the mile-long translucent Martian worm.
On Hoagland's web site, there are several images from various space probes said to possibly show evidence for ET. Recent Mars rover photos include not just rocks, Hoagland and other contributors maintain, but common objects that might tell of alien civilization -- a bowl, a stove, a piston.
I can safely say that I have never heard the word "pareidolia" before.
You may be wondering at this point what this has to do with archaeology. Lots actually, in two respects. First, pareidolia is also seen in archaeology, most notably in cases where there are supposedly ancient "roads" or "buildings" seen underwater, and often used as evidence for mysterious ancient civilizations (let's all say it together: Atlantis!). The concept of an "artifact", that is, a man-made object or feature, can get pretty dicey when the objects in question are very simple. The earliest stone tools, for example, are extremely simple little things, just a rock with a couple of chips taken out of one side. Often, people see artifacts where there aren't any at all. In these cases, a certain conservatism is necessary, especially when the "artifact" is controversial for other reasons (in deposits where it shouldn't be, for example). Generally, the bar gets higher for proving artifact-ness and one must demonstrate to a high degree that no known natural process could have created the object.
Second, the methods used will be familiar to those dealing with archaeological psuedoscientists along the lines of Erich Von Daniken, Graham Hancock, etc. Take, for example, the Coso Artifact which several have taken as evidence that an advanced civilization was creating spark plugs 500,00 years ago.
Critical thinking should never be in short supply, whatever the planet.