Mars rover tracks spell out Morse code message (+video)
During its first test drive on Mars, NASA's Curiosity rover left a Morse code imprint on the Red Planet's surface, a tribute to the one-ton robot's maker.
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On Wednesday (Aug. 22), the car-size, six-wheeled rover took its first test drive since arriving on the Red Planet more than two weeks ago. Its drivers back on Earth ordered Curiosity to roll forward about 15 feet, (4.5 meters), turn right and then back up about 8 feet (2.5 m), such that when the robot stopped it was positioned to the left and roughly perpendicular to where it touched down inside Mars' Gale Crater.
"You can see in the tracks how we drive forward, and then you can see roughly a circle, which is where the rover did what we call its turn-in-place maneuver," said lead rover planner Matthew Heverly, of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "So it steered all of its wheels and then performed a turn of a 120 degrees, pivoting about a point in the center of that circle, and then it backed up."
Curiosity's path to its new parking spot was emblazoned on the Martian surface by a series of dash and dot tread marks left in the soil by each of the rover's 20-inch diameter (50-centimeter) wheels. [Photos from Curiosity's First Drive on Mars]
The track pattern — dot-dash-dash-dash, dot-dash-dash-dot, dot-dash-dot-dot (".--- .--. .-..") — spells out "JPL" in Morse code, which translates letters and numbers into a series of short ("dot") and long ("dash") signals.
Curiosity's signature wheel-print was a nod to NASA's lead center for unmanned planetary exploration, which built the rover and now commands it as Curiosity prepares to explore Mars in search of conditions habitable to past or present life.
The dashes and dots are more than just an autograph on the ground. They serve as "visual odometry" marks, which allow Curiosity's engineers to determine the position and orientation of the rover, as well as how far it traveled, by analyzing images of its tracks.
"We have intentionally put holes in the wheels to leave a unique track on Mars," Heverly said. "So if we are in sand dunes where we don't have lots of rock features around us, we can use those patterns to do our visual odometry."
In addition to the Morse code JPL, Curiosity's wheels also feature a zigzag cleat pattern.
Check out, then roll out
Curiosity's short test drive was the latest in a series of instrument and equipment checkouts that the rover needs to pass before heading out toward its first major science target.
Earlier this week, Curiosity extended its 7-foot (2.1-m) robotic arm, which is capped by a turret of tools including a camera, drill, spectrometer, scoop and the mechanisms for sieving and portioning samples of powdered rock and soil.
"We unstowed the robotic arm and took a look at the tools on [its] end. It's kind of a Swiss army knife there where we have a lot of instruments," said Curiosity mission manager Michael Watkins of JPL. "We wanted to make sure all of that was working by doing these first motor checks, and all of that went successfully."