NASA / JPL / Cornell When some people look at this nine-year-old picture from NASA's Spirit rover, they see a graphic depiction of manhood. Actually, it's standard operating procedure for making a turn on Mars.





Some Mars maniacs just won't grow up: A picture of the track patterns left behind by the Mars rovers' standard turning maneuver has drawn giggles and gasps — merely because it looks like a penis scrawled on the Red Planet.

"The rude drawing has emerged in a series of images taken by one of its rover machines. ... The latest pictures beamed back from one of the rovers show signs that the project's controllers have started to get a bit bored," The Sun, a British tabloid, reported on Wednesday.

Even Sarcastic Rover, one of Twitter's top parody personas, got into the act: "Since everyone's asking, let me just say that some other robot did this ... definitely not me," it tweeted.

The jibes from Sarcastic Rover and The Sun, and tons more like them, were sparked by a Reddit forum's discovery of the picture the day before. But this picture isn't the product of a bored (or filthy-minded) rover driver, and it wasn't beamed down recently. It's part of a classic nine-year-old panorama from NASA's Spirit rover, looking back toward its landing platform. (You can actually see the platform in the high-resolution version of the panorama.)

This type of rover wheel-track pattern, which could euphemistically be called "a bat and two balls," has been left on Mars many times, not only by Spirit (which gave up the ghost in 2010 or so), but also by Opportunity (which is still going strong more than nine years after landing on Mars) and Curiosity (which landed last year).

All those rovers have six wheels, three on each side, and they leave behind two parallel tracks when they're traveling in a straight line. When the rover has to make a turn, the wheels rotate in place to put the robot in the desired direction for the next leg of its trek. If the turn is significant enough, you get a nice set of circles at the end of a pair of parallel tracks.

Got it? Now we can move on — for instance, to lewd pictures from the Hubble Space Telescope.

NASA / ESA / STScI / AURA / La Plata Obs. A sub-cloud of dust in the Carina Nebula displays what some have called "the cosmic finger of friendship."

More tracks from the Red Planet:

Tip o' the Log to Jia-Rui Cook at NASA's Jet Propulsion Laboratory for finding the original Spirit panorama from Mars.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.