A portion of the tread pattern on the wheels of NASA/JPL's Curiosity Mars rover consists of a series square and rectangular holes that according to the Chuck Norris-looking guy on the embedded video (below) serve as "visual odometry marks." They are arranged in an asymmetric pattern on the rover that will leave an imprint on the surface of Mars so the onboard cameras can look at them to determine whether the craft is actually traversing the distance it is being commanded to move. Less distance between sets of marks are an indication that slippage is occurring. If that happens and Curiosity cannot correct itself, it will stop and make a call back home to JPL and await further instructions. The round-trip call can take anywhere from about 6 minutes to more than 44 minutes depending on the two planet's orbital positions, not including the time needed to formulate a reply.
Look more closely at the "visual odometry marks", however, and you will notice those holes are squares and rectangles that make up dots and dashes, respectively, for Morse code. The succession of three rows spells out •−−− •−−• •−•• (JPL). Clever, non? Just as aliens live among us largely undetected, so too do amateur radio operators. Occasionally a breadcrumb is left behind that the keen observer will recognize. Agent K knows a refugee from the planet Zorg when he spies one mingling with Earth's population. Likewise, Hams immediately recognize Morse code when they see or hear it - sometimes even when it is not really code at all. It is surprising that the narrator of the video does not mention the coded impressions.
Unlike on the moon, wheel-prints made by Mars rovers will not last forever because Mars has an active atmosphere like the earth. Erosive winds will soon wipe away all evidence of its path. Future visitors to Mars, be they from Earth or from the planet Zorg, will find no trace of our rovers. With the passage of time, wind-blown sands will cover not just the tracks on the surface, but the machines themselves.
Not long ago I posted a picture of Morse Code appearing on a sidewalk bench in New Zealand. Have you spotted any other instances of Hams overtly making their presence known?
Posted August 16, 2012