image title
Lunar images from ASU team combine an artistic eye with precision science.
It's time to send people back to the moon, ASU professor Mark Robinson says.
Smithsonian Air and Space exhibit will feature 61 images from ASU-based team.
February 24, 2016

ASU professor hopes Smithsonian exhibition of LROC team's striking images gets people excited about returning to the moon

Sometimes you get the party started by accidentally crashing someone else’s.

Mark Robinson, a professor in Arizona State University’s School of Earth and Space ExplorationThe School of Earth and Space Exploration is an academic unit of the College of Liberal Arts and Sciences., was enjoying a First Fridays art walk in downtown Phoenix during the summer of 2012 when he wandered into monOrchid gallery on Roosevelt. Only the gallery wasn’t open to the public that evening.

“I realized I had just crashed someone’s private party,” Robinson said.

He spoke with someone on the edge of the crowd, who turned out to be the gallery’s owner. Robinson — principal investigator for the ASU-operated cameras aboard NASA’s Lunar Reconnaissance Orbiter (LRO) — introduced himself and the mission’s photographs, saying he thought they’d make for a great exhibit.

“He was polite, but I think he kind of thought I was … kind of wacko,” Robinson said.

But when he brought in photographs to show the owner and unrolled a 12-foot-long, high-res version of the Tycho crater’s central peak, Robinson recalled, “All he said was, ‘Do you want to do this in October or November?’ ”

That exhibit, which drew thousands of visitors, was the first step on a journey leading to this Friday’s opening of “A New Moon Rises,” an exhibit of 61 images from the Lunar Reconnaissance Orbiter Camera (LROC) at the Smithsonian National Air and Space Museum in Washington, D.C.

Robinson hopes it gets people excited about the moon again, in an age when many eyes are turned toward Mars and the thought of manned flights there.

“The moon is this beautiful little world,” Robinson said. “It’s not just a romantic silver disc you see in the sky at night; it’s a world in its own right. And it’s somewhere we should be going back to.”

Small crater on rim of Chaplygin crater on the moon.

Though it might appear a
bit like the Eye of Sauron,
this LROC image is of a
small crater on the rim
of Chaplygin crater.

Photo by NASA/GSFC/
Arizona State University

The LROC’s thousands of images — curated on the team’s website — are often a blend of science and artistry. Tom Watters, senior scientist at the museum’s Center for Earth and Planetary Studies and curator of the exhibit, said one of goals of the Smithsonian event is to “captivate the visitor with the sheer beauty of the landscape of the moon.”

“If it’s lit in a certain way from the high sun angles, you get these wonderful variations in the brightness of the materials, and those can be very surreal-looking,” Watters said. “And if you have the dusk-to-dawn lighting, with the low sun angles with the shadows being cast, the incredible details in the landscape come out.”

He credits all those on the LRO team — the sheer amount of work involved often isn’t obvious to the general public — but said Robinson deserves a large portion of that praise.

“If it wouldn’t embarrass him, he really is the Rembrandt of capturing just the right kind of lighting,” Watters said. “He’s the maestro, the master of doing that.”

The artistry makes sense with Robinson’s background — he didn’t originally intend a career in space. His first college degree was a double major in political science and fine-art photography.

But luckily for the scientific community, that original career path didn’t result in any real jobs. “I was always interested in science,” he said. “… I somehow got into college and did the wrong thing.”

A chance conversation with a friend at a summer construction job led Robinson to Alaska, where he worked with geologists and discovered the field that would take him, metaphorically at least, into the heavens.

A man stands in front of monitors showing moon images.
ASU professor Mark Robinson in the Lunar Reconnaissance Orbiter Camera Science Operations Center, on the ASU Tempe campus. Photo by Charlie Leight/ASU Now

 

His association with the Smithsonian goes back decades, but this is his first exhibit there.

“My hope is that we’re going to get millions of people — maybe I’m being a little optimistic — totally excited about the moon,” Robinson said. “The moon will be a new place. They will realize the moon is a magnificent world in its own right. It’s a world in change right now.”

More than 200 new craters have been imaged since the LRO started orbiting, Robinson said. Another surprise to scientists has been evidence of very young volcanism there, changing the previously assumed timeline that lunar volcanism ended 1 billion to 2 billion years ago.

“It really transforms the moon in my mind,” Watters said. “ … The moon is still alive. There’s still a lot going on there. It’s not a dead object at all.”

The LRO cameras, which were fabricated by Malin Space Science Systems, send back 450 gigabits (about 56 gigabytes) of science data every day and have been doing so for six and a half years. It’s more than all other NASA planetary missions throughout history combined, Robinson said.

About 90 percent of the data flow is automated, both the uplink and the processing. “We couldn’t keep up with it otherwise. It would be like trying to catch Niagara Falls with a 5-gallon bucket,” he said.

Even with that automation, it takes a team of 30 people, including about a dozen undergraduate students, to keep the project humming. Each image must be planned — not only the location for visual or scientific purposes and what the lighting will be, but even down to what the temperature will be at the moment the image is captured, as that can affect other components. The oblique images’ composition especially receives an extra level of review.

Antoniadi crater wall on the moon.
In this oblique view, the 4,000-meter-tall cliff in the background is the east wall of Antoniadi crater, which is 140 kilometers in diameter. The bottom of the small bowl-shaped crater tucked behind peaks in the center ground is the lowest point on the moon, more than 9 kilometers below the mean radius (comparable to sea level on Earth). Photo by NASA/GSFC/Arizona State University

 

The images are incredibly crisp, especially considering that the spacecraft is moving at 1,600 meters per second — more than 3,500 miles per hour. The team needed an effective exposure time of 0.3 milliseconds, three times shorter than the fastest of cameras available.

They achieved that, and the result is photographs of incredible depth and variation in tone. Shadows and highlights reveal detail, and some of the images appear more like modern art than science resource.

The exhibit, which will run at least through December, will include a state-of-the-art laser projector showing the latest LROC images, a large 3-D model of a lunar crater and an interactive kiosk that allows visitors to explore more of the LROC data. A similar one stands in the visitor center in Interdisciplinary A on the Tempe campus.

Robinson hopes the beauty of the images draws visitors in, and that the delight in seeing LROC images that show the human and rover tracks from Apollo missions sparks questions as to why we aren’t returning there.

“How do you really top human beings for the first time walking on another world?” Robinson said. “But now that’s 47 years ago. It’s time to go back in a different manner, a more measured manner. …

“The time is right now to start heading back, not to plant a flag and pick up a few rocks, but this time for sustained exploration and sustained science. And that will enable us to go to Mars and even farther out into the solar system.”

Top photo: In this view of the moon, the South Pole is at the center. The colors represent different elevations. The large, roughly circular, low-lying area (deep blue and purple) is the South Pole–Aitken Basin, the largest and deepest impact feature on the moon. Photo by NASA/GSFC/Arizona State University

One rule to grow them all: Using 'baby' teeth to predict hominin tooth size


February 24, 2016

What regulates the size of an organism’s teeth? The reduced size of our back teeth, or molars, is one of the defining attributes separating modern humans from hominins (our extinct relatives). The earliest hominins, known collectively as australopiths (best exemplified by “Lucy,” a member of the species Australopithecus afarensis), had larger teeth overall and their largest molar was positioned closer to the rear of the mouth. Fossil species within our own genus, Homo, not only had smaller teeth, but their biggest molar was situated closer to the middle of their jaw.

This trend of reduction in molar size continues in modern humans, where some of us may never develop our rearmost molar, or wisdom tooth. While these differences have been traditionally linked to variations in function and diet, constraints during dental development play an important role in how and why teeth grow to be a certain size. Download Full Image

A new study by an international team including ASU researchers published in the journal Nature, combined tools from embryology, comparative anatomy and computational biology to reveal that a single embryonic rule has regulated hominin tooth size. In addition, it is a subtle alteration in the expression of that rule that accounts for the varying patterns in tooth size encountered throughout the entire human evolutionary story.

“One of the more exciting findings of this new study is that the size of teeth, including the molars, in modern humans and all fossil hominins, conforms to the predictions of just one simple, elegant developmental rule called the ‘inhibitory cascade’,” said Gary Schwartz, a coauthor and paleoanthropologist with the Institute of Human Origins and School of Human Evolution and Social Change. 

“Under this simple rule, discovered in earlier research in mice, the size of one molar regulates the development of its neighbors, constraining the sizes of subsequently developing teeth,” added Susanne Daly, a coauthor and ASU doctoral candidate in evolutionary anthropology.

While paleoanthropological interest in this dental development rule focuses mostly on adult teeth, the researchers had a hunch that this was only part of the story.

“Most mammals, including all living humans and all extinct human ancestors, have two sets of teeth: a milk set, or ‘baby’ teeth, and an adult set,” said Kierstin Catlett, a coauthor and ASU doctoral candidate in evolutionary anthropology. “Milk molars and adult molars are both critical elements for breaking down food to fuel an individual’s growing body and brain.”

 

Milk teeth and adult molars

 

“As milk teeth and adult teeth develop side by side within growing faces, it is not surprising to think that one set has a powerful influence on how the other set develops,” added Schwartz.

The researchers found strong evidence that the inhibitory cascade pattern for adult molars was a direct outcome of how big their milk molars are.

“Amazingly, the size of milk molars, which start developing prior to birth, have a powerful cascading effect on the size of later-forming adult molars,” said Catlett.

This result encouraged the team to examine fossil hominin teeth from across the last 5 million years, focusing now on milk molars and adult molars together, as a developmentally linked set. They found that australopiths tended to follow one pattern, while sometime after 2.8 million years ago, a new pattern emerged in members of our own genus Homo. This suggests that selective pressures leading to this shift in pattern were a key adaptation in the lineage that eventually led to modern humans.

“One important implication of this work is the predictive power of the model, which now allows paleoanthropologists to predict the size of missing fossil teeth,” said Kathleen Paul, a coauthor and doctoral candidate who works with the School of Human Evolution and Social Change's Center for Bioarchaeological Research.

There appears to be a coordinated developmental dance between milk and adult teeth, such that slight deviations can produce profound downstream changes.

“What is really exciting is that our results fit an emerging picture that only a very small amount of tinkering during development, not a wholesale reorganization, is enough to generate a whole range of different anatomies, including the vast diversity in tooth sizes of our ancestors,” said Schwartz.

 

The Institute of Human Origins is a research center of the College of Liberal Arts and Sciences. The School of Human Evolution and Social Change and its Center for Bioarchaeological Research are both part of the College of Liberal Arts and Sciences.

Julie Russ

Assistant director, Institute of Human Origins

480-727-6571