“Duluth” is now a tourist attraction on two different planets, the Duluth News Tribute proudly reports. The NASA research team that operates the ChemCam instrument on the Mars Curiosity rover has decided to name a three-foot long slab of martian rock after the iconic city in Minnesota.
The decision was motivated by a couple of similarities between the port city and the newfound chunk of sedimentary rock, which was discovered earlier this week and has become the newest drilling target of the Mars Curiosity rover.
The rover stumbled upon the desk-sized slab of rock while trekking down the lower slopes of Mount Sharp inside the Gale Crater. As the Inquisitr reported last week, the rover switched direction in April and began descending along Vera Rubin Ridge to look for a great new target on which to test its upgraded percussion drilling technique.
The martian chunk of rock that was later named “Duluth” was spotted in the Murray Formation, a 1,000-foot-thick layer of sedimentary rock located on the mountain’s lower side.
The Duluth rock is estimated to be 3.5-billion-year-old and was formed, just like the entire Murray Formation, by sediments deposited on the floor of the ancient lake that once filled the Gale Crater on Mars.
This connection to a freshwater lake, albeit one that dried billions of years ago, is the first similarity between the martian rock and the U.S. port city that stretches along the shore of Lake Superior.
ChemCam project leader Roger Wiens, who hails from Duluth himself, said he “was excited” to hear that the newly-chosen drill site was named for his native city, which “is still considered the largest freshwater port in the world,” he pointed out.
In a NASA blog post detailing the activity of the Mars rover on Sol 2055, Wiens commented on the team’s reasons for choosing this particular moniker, which is yet to be approved by the International Astronomical Union.
“Duluth has one of the coolest climates in the U.S. due to its proximity to the world’s largest and one of the deepest freshwater lakes. The drill target ‘Duluth’ on Mars was also once near the shore of a large freshwater lake. Its climate is also relatively cool, so the name is apropos.”
Aside from present and past exposure to water, the two Duluths have one more thing in common: a geological feature that inspired the team to make this interplanetary connection.
The city of Duluth lies on a vast crystalline volcanic rock formation known as “gabbro,” which makes up the Duluth Complex stretching not only beneath the city, but along the entire northern shore of Lake Superior.
The city’s dark sedimentary bedrock is evocative of the process through which the martian Duluth, also a sedimentary rock, was formed. According to Wiens, the Duluth on Mars “appears to be almost entirely lake-bottom sediments.”
“A fair amount of this sedimentary rock has been relatively soft, and it consists of very thin layers about a millimeter (1/25th of an inch) thick. The large number of layers suggests that the lake was there a long time,” he told the Duluth News Tribute in an email.
The Curiosity rover’s next goal is to start drilling at the new site and hopefully recover a sample of the Duluth rock, which would be stored in the robot’s internal lab and subsequently analyzed in full detail.
The rover has already used its ChemCam instrument to fire laser beams at two targets located on the Duluth block, namely “Pine Mountain” and “Windigo,” team member Rachel Kronyak noted in a previous NASA blog post.
This process enables the team to identify the composition of various rock and soil samples, by analyzing the color of the gas that emanates when the lasers vaporize a small piece of their target.