Wednesday, August 9, 2017

NASA MARTE

Similarities to Missoula megaflood seen on Mars, elsewhere on Earth

NASA officials didn’t disguise their excitement last week in describing the 600-mile-wide flood scar they’ve mapped on the surface of Mars.
Here in Missoula, we can casually reply: Live here, seen that.
And there it was in the NASA news release: The Martian flood channel was “comparable with the depth of incision of the largest known megaflood on Earth, the Missoula floods, responsible for carving the Channeled Scabland of the northwestern United States.”
Members of the Glacial Lake Missoula Chapter of the Ice Age Floods Institute have seen that coming since the Viking Lander touched down on Mars back in 1976.
“It’s frightening to think how long we’ve been at this,” said Norm Smyers, a retired U.S. Forest Service geologist and member of the Glacial Lake Missoula chapter. NASA suspected the Marte Vallis region of Mars was a megaflood zone back when it was planning the Viking missions. And thanks to what was known about the Missoula floods, that became the target for the first landing.
“They recognized from earlier overflights that some of the features looked very reminiscent of the scablands we see in eastern Washington,” Smyers said. “So they brought a model rover to that terrain to see how it would do the job. A bunch of T-shirts came out of that.”
The channeled scabland of central Washington bears erosion scars from what geologists suspect was a three-day flood that emptied Glacial Lake Missoula about 14,000 years ago.
The lake was 2,500 feet deep and spread over 3,000 square miles – roughly half the volume of present-day Lake Michigan. When the ice dam restraining it blew out, 530 cubic miles of water tore west at more than 65 mph, all the way to the Columbia River drainage.
Missoulians see the lake’s shorelines in the sedimentary lines on Mount Sentinel and Mount Jumbo, and in the chasm of Alberton Gorge.
But why would such a flood zone be a good landing spot on Mars?
“When you go to eastern Washington, the predominant rock type is basalt,” Smyers said. “But you do get a few rocks from northern Idaho and Montana mixed in. That’s why they landed the first rover where they did – they’d encounter something other than the rock where they landed. They wanted somewhere where a lot of stuff was around representing other areas.”
NASA’s fascination with the Marte Vallis continues. Its latest endeavor used a special radar to probe subsurface geology and create a 3-D map of the region. This exposed the structures underneath a surface layer of lava, revealing water-carved channels 26 to 371 feet deep. The erosion happened between 10 million and 500 million years ago.
That’s long after the period when NASA scientists suspect Mars might have had life-supporting water supplies on its surface, 3 billion to 4 billion years ago. The new 3-D maps indicate Mars may have had underground water activity miles below the planet’s surface.
Which brings us back to Missoula. Glacial Lake Missoula chapter president Jim Shelden said the Martian research could explain some puzzling Montana landforms and give insight to potentially catastrophic climate change effects.
“In computer simulations, if you start at the (Columbia River) Gorge end and work backward, you get a lot more water than if you start at the Lake Missoula end,” Shelden said. Where did the extra water come from?
Studies in Antarctica and Greenland indicate ice sheets can trap huge bodies of water within or beneath their structures, Shelden said. Outbreak floods there may have halted ocean currents, triggering planetwide climate shifts in the past.
Now the Martian observations appear to show massive floods can happen underground. What if the same thing happened with ice-covered lakes in Ice Age Montana?
“There are other features that appear water-related from something Lake Missoula-sized, but they didn’t match,” Shelden said. “Maybe they are evidence of floods trapped between ice and the Earth’s surface. That’s a new, emerging story, and the story is getting richer and more detailed as we get feedback from climate change.”
“The big deal it’s leading to is the idea that big outburst floods are a huge process worldwide,” Shelden said. “They’re a much bigger deal than we gave them credit for. We ought to know about them.”

UA team preparing for NASA robotics competition

By Drew Taylor Staff Writer
At about 1 a.m. Monday, Rebecca Dietz noticed something wrong with “MARTE.”
Dietz, a senior studying mechanical engineering at the University of Alabama, and several other members of the Alabama Astrobotics team were testing “MARTE,” a robotic excavator they had built, in the back of Hardaway Hall when the digging belt broke.
The team put the belt back together, but the development was an example of how engineers constantly work on their projects.
“If we don’t break it, we’re not testing it right,” said Kenneth Ricks, associate professor in the Department of Electrical and Computer Engineering and the head of the team.
For months, the team has been prepping “MARTE,” or modular autonomous robotic terrestrial excavator, for the upcoming NASA Robotic Mining Competition next week at the Kennedy Space Center in Titusville, Florida. The 17-person team will depart for the competition Saturday, where they will test "MARTE" to dig in conditions similar to a Martian landscape.
NASA has been holding the competition since 2010 in an effort to crowdsource ideas for how to move dirt on planets such as Mars. Since its inception, the UA team has won the competition three times and the majority of its members have competed two or three times before.
“This is the conglomeration of about eight years’ worth of ideas,” Ricks said.
The competition judges robots based on their weight, how much the machines can dig in a 10-minute span and how autonomous they can be, not requiring the need of someone controlling it to make it work.
“MARTE” weighs 45 kilograms, or approximately 99.2 pounds, and is 1.5 meters long and .75 meters wide. Ricks said the best record the robot has completed in its trial run is moving approximately 200 kilograms of sand in 10 minutes, or approximately 441 pounds.
“If we can do that at the competition, we will be thrilled,” Ricks said.
The challenge for the team will be ensuring that “MARTE” autonomously travels its first run.
“With 50 teams each year with two chances and 700 attempts, full autonomy has happened only twice,” Ricks said. “It’s hard.”
Joe Kabalin, a recent graduate on the team, said being on the team has given him a lot of opportunities to explore engineering. This summer, he will serve an internship with Caterpillar and then go to graduate school at Georgia Tech.
“It gives you experience outside of the classroom and gives you some hands-on team working,” Kabalin said.
Jonathan Blake, a freshman studying electrical engineering, will join the team for his first competition this year.
“It’s been a truly great experience working with a team and seeing this project come together,” Blake said. “It’s been a good experience.”
Dietz said she would love to explore building robots for NASA one day, but that projects like “MARTE” have taught her what she wants to do as an engineer.
“I think that teams like ours are good ways to figure out what you like because it gives you areas to try and see if you like something,” Dietz said. “If I did this every day for a living, I would be happy.”
The competition will last from May 22 to May 26.
Ricky said the team and competition is the best education he can provide to his students.
“They just don’t talk about something working; they have to make it physically work,” he said. “There is no substitution for that.”
Reach Drew Taylor at drew.taylor@tuscaloosanews.com or 205-722-0204.

A Glimpse of Channels Hidden Under Mars' Surface

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Channels that run beneath the surface of Mars, evidence of a time when the planet was full of water, have mostly remained mysterious to NASA researchers. For instance, Marte Vallis, a 1000-kilometer (621-mile) channel near the planet's equator, has been impossible to study because it is buried beneath some of the youngest lava flows on the planet.
Now, scientists are learning to look beneath the surface. A team led by the Smithsonian Institution's Gareth Morgan has used the Shallow Subsurface Radar—known as SHARAD—on board the NASA Mars Reconnaissance Orbiter to probe the Marte Vallis.
SHARAD, provided by the Italian Space Agency and operational since November 2006, studies the surface of Mars by sending out a 15–25 MHz frequency band. Its antenna captures the radar wave as it returns. Some of the radar bounces back after hitting the surface, but other frequencies in the band will make it through to the channel, reflecting off its base instead. By measuring the time delay, researchers can determine what kind of material they've hit (such as dense rock, liquid water, or ice) and map the topography of the planet.
SHARAD is designed to cut as deep as 1 km, as it's under the surface that researchers hope to find ice. Morgan tells PM that the returning echoes give the researchers tracks of data across several hundreds of kilometers, producing slices into the subsurface and providing cross-sectional images. After filtering out noise and other interference, they have a picture of the subsurface.
"It's hard to look at these and see where the channel is," he said, "but we took each slice and mapped out where we thought we saw channels. Then, when we used software to spatially align the slices, we could see where the channels we'd marked were lining up from track to track."
3-D visualization of the buried Marte Vallis channels beneath the Martian surface. Marte Vallis consists of multiple perched channels formed around streamlined islands. Credit: NASA
Once they'd produced a final image, the team made several new discoveries about the channel. The channels proved to be twice as deep (18 meters, or about 60 feet) than previously assumed, and the system was much more complex than anyone had guessed. Most important, Morgan and his team found the source of the channel, which had been a cause of debate. Some scientists thought the water originated from a standing body, like a lake, that overflowed, while others though it came from the Cerbrus Fossae, a series of fissures. It was thought that the fissures never actually cut across the path of the channel, but SHARAD showed that it did a full 180 km (112 miles) to the east.
Until now, SHARAD's main purpose has been to seek out water and ice on Mars, not to explore its subsurface tunnels and caverns. Morgan hopes his work, published today in Science, will change that.
"This kind of 3D reconstruction hasn't been done with SHARAD previously," he said. "This shows that we can use this radar to look for buried channels." That, he says, is the next step in understanding the hydrology of Mars.

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