NASA has captured some images on Mars. They appear to show a Bigfoot type creature walking on the surface of the red planet. (I am not making this up! Check out Bigfoot on Mars? NASA captures alien figure. I believe this news site is a credible source.)
I imagine this is probably an optical illusion and the image is of a rock. However, this photo could be used as a teaching tool for critical thinking. Take this picture and compare it in class to other long range purported photos of Bigfoot. There are many out there to be found by doing a Google Image search on Bigfoot or Sasquatch. Find a few that look similar to the NASA Mars photo. Ask the students if the Martian photo is Bigfoot. Then ask the students if the Earth photos are of Bigfoot. I believe this could generate some good discussion and allow the instructor to introduce critical thinking ideas.