Smaller asteroids, bigger problems
Once in a lifetime, a physicist may get a chance to test his theories and simulations in a real-life event that changes the course of his scientific life. But rarely does that opportunity literally fall from the sky.
That’s the impact of the Feb. 15 asteroid that burst over the Russian city of Chelyabinsk on Sandia physicist Mark Boslough (1442), subject of a TV documentary that aired this month and co-author of a recent cover story in Nature about the asteroid fireball that injured about 1,500 people and damaged more than 7,000 buildings, collapsing roofs and breaking thousands of windows.
Mark’s journey to Russia shortly after the impact is chronicled in the NOVA episode “Asteroid: Doomsday or Payday,” which was initially broadcast on PBS on Nov. 20 and is available for viewing online.
The show focuses on the destructive potential of asteroids, chronicling how Mark and his colleagues learn that small asteroids can do far more damage than previously thought. The Nature paper also suggests that there may be more small asteroids than formerly thought.
The day the asteroid hit, Mark learned of the event via Facebook from posts of Russian news stories and YouTube videos showing an object that exploded in the Russian sky.
“I saw it on Facebook long before the sound wave had even arrived in this part of the world,” Mark says, estimating the transglobal sound wave took more than seven hours to reach New Mexico. “I really didn’t expect to experience this in my lifetime.”
As one of the first scientists to visit Chelyabinsk after the asteroid struck, Mark set out to discover where the object came from. Because it came down near a populated area, he and his colleagues were able to collect videos from people who caught the asteroid on film and video, especially the ubiquitous Russian dashboard cameras, a staple in establishing blame in traffic mishaps.
“This event was certainly one of the best-documented asteroid events ever,” says Mark.
Mark’s goal was to perform stellar calculations of the asteroid’s trajectory by visiting — at night when the stars shone — the exact spots where the footage was recorded.
“If the stars show up on the digital camera, we can get those angles and then calibrate that image that was taken from the dash cam, and know exactly the angles to the trajectory of the fireball,” he said in the documentary. “We’ll have a very precise trajectory as it streaked through the atmosphere, so we can backtrack that to get the orbit, the pre-impact orbit.”
The program also discusses how asteroids can contain rare and valuable elements, leading researchers to seriously evaluate the benefit of harvesting them.
But Mark also wants the research community to pay more attention to the potential risk that asteroids present.
“If something like the Tunguska event of 1908 happened now, it could kill hundreds of thousands or even a million people, if it happened right over a big city,” he said in the documentary. “An asteroid has more damage potential on the ground than a nuclear bomb of the same energy.”
Mark was part of a team of 33 researchers who completed the study featured in Nature. “A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors” examines the characteristics of the fireball. Mark and his colleagues also used the simulations to help design the journal’s cover.
(You can see an animated simulation of the airburst produced by Mark, as well as scientific animations and images by Sandia contractor and visual effect expert Brad Carvey and visual effect expert Andrea Carvey.)
Sandia’s Laboratory Directed Research & Development program funded the simulations.
Using data collected from his visit shortly after the asteroid struck, along with data from an international team, Mark developed several additional simulations that he and other researchers have used to model the explosion and estimate the force of the blast.
The paper’s authors performed a global survey of airbursts of a kiloton or more and found that the number of building-sized objects may be 10 times greater than estimates based on other methods.
The authors, led by Peter Brown of the University of Western Ontario, estimated the Chelyabinsk event was equivalent to an explosion of about 500 kilotons of TNT. At its peak, the airburst appeared to be 30 times brighter than the sun.
“Because the frequency of a strike of an asteroid of this size has exceeded expectations, with three such strikes in just over a century (Chelyabinsk, Tunguska, and a large airburst in the South Atlantic in 1963 detected by infrasound), the number of similar-sized asteroids capable of causing damage may be greater than suspected,” Mark says.
Dick Spalding (5730) of Sandia’s Nonproliferation Technologies Research and Development Department also co-authored the paper.
The Nature authors showed that previous models for estimating airburst damage do not match the observations.
An earlier paper by Mark highlights the conclusion that most airbursts are more damaging than previously thought.
“We really have to rethink the risk from airbursts. Chelyabinsk was unusual due to the a low inclination at which it entered the atmosphere, but 90 percent of objects enter the atmosphere at a steeper angle and cause more damage on the surface,” Mark says. That paper, which he wrote two years ago, was recently published online in Acta Astronautica.
The Chelyabinsk fireball is something those who saw it will never forget, and neither will Mark.
“What’s amazing to me, though, when you think about it, this is part of an asteroid that had been floating through space, orbiting the sun for billions of years,” he said for the documentary in a late February interview. “And two weeks ago, it exploded in the atmosphere, dropped to the ground, and here I am holding it in my hand! That’s amazing.”
-- Jim Danneskiold and Stephanie Holinka
Partners in progress: Sandia joins effort to launch statewide R&D council
by Nancy Salem
Sandia President and Laboratories Director Paul Hommert told the inaugural summit of the New Mexico Collaborative Research & Development Council that its members have the resources to advance the state’s contributions to science and technology.
“We have mechanisms in place,” Paul said. “We can use our respective strengths.”
Sandia is one of nine institutions invited by US Sens. Tom Udall and Martin Heinrich, both D-N.M., to join the council. Other members are Los Alamos National Laboratory (LANL), the University of New Mexico (UNM), New Mexico State University (NMSU), New Mexico Institute of Mining and Technology, Air Force Research Laboratory, Kirtland Air Force Base, Holloman Air Force Base and the 96th Test Group, and White Sands Missile Range.
Among those attending the meeting, in addition to Udall, Heinrich, and Paul, were UNM President Bob Frank, NMSU President Garrey
Carruthers, New Mexico Tech President Daniel Lopez, LANL Director Charlie McMillan, and Holloman AFB Commander Col. Andrew Croft.
Partnerships increasingly critical
The council encourages collaboration on research, development, test, and evaluation emphasizing critical areas related to national science and technology priorities. Udall and Heinrich said establishing and building on strategic partnerships across the state is increasingly critical as institutions face shrinking budgets and competitive funding.
“The council can help ensure that New Mexico not only retains, but enhances, its competitive position and potential for scientific contribution, economic growth, and workforce development,” Udall said.
Heinrich added, “Now more than ever we need to collaborate with the challenging fiscal constraints that exist.”
The council will meet quarterly to set goals and direct collaborative work statewide. Each member appointed two representatives to the group. Paul named VP and Chief Technology Officer Julia Phillips and Carol Adkins, director of Materials Science and Engineering Center 1800.
Julia said Sandia recently teamed with UNM to hire an individual who will work in advanced energy materials part-time at both institutions. “With this kind of collaboration we can attract people we might not be able to get by ourselves,” she said.
Paul said Sandia has R&D memoranda of understanding with UNM, NMSU, and New Mexico Tech. “We need more,” he said. “By engaging in an active dialog through the council we can take existing collaborations to a higher level.”
Udall said the state must double the number of students who graduate in science, technology, engineering, and math (STEM) fields. “Everyone here has a need for those graduates,” he said.
Paul said the state’s research universities are Sandia’s main source of hiring. “We have a shared set of equities in our success,” he said.
Commitment to economic development
UNM’s Frank said council members will commit to making the New Mexico technology corridor along the Rio Grande Valley from NMSU to LANL a national leader in R&D. “We’re making a remarkable commitment to collaborate to raise New Mexico up,” he said. “We’re prepared to lead in technology advances.”
Council members talked about the importance of creating private sector jobs. Paul said Sandia is committed to technology transfer, industry partnerships, and economic development.
Heinrich said the council “must focus on STEM and technology transfer to grow the private sector.”
“New Mexico has a proud history of scientific discovery, innovation, and technology that has long served as an engine for economic growth,” he said. “The council, whose members include some of the nation’s leading scientific minds from some of the nation’s most prestigious research institutions, will facilitate research collaborations and strategic partnerships that will allow this culture of innovation and discovery to thrive in New Mexico even during times of fiscal uncertainty.”
-- Nancy Salem
Sandia wins two Popular Science Best of What’s New awards
Sandia’s fiber optic network won Popular Science’s Grand Award for Engineering when the magazine released its Best of What’s New 2013 winners. The magazine also awarded Sandia’s non-detonable fertilizer a Best of What’s New citation, in the security category.
Each year, the editors of Popular Science name 100 innovations in the material world that they say are reshaping the future right before our eyes. According to the magazine, “Best of What’s New winners make our world and our lives safer, more efficient, and straight-up better than we thought possible.”
1 gigabit per second
In the case of Sandia’s fiber optic network, the system is the breakthrough, with the most obvious attribute being the scale. The Labs integrated an Internet service provider (carrier class) core with a passive optical distribution network. Sandia built the world’s largest enterprise passive fiber optic local area network, with high-speed connections for 265 buildings and 13,000 end-users, each with a hookup capable of 1 gigabit per second. It replaced its conventional 4-inch copper cable with a half-inch fiber-optic one capable of transferring voice and computer data along a single line. The network also can deploy next-generation XG-1 or XG-2 passive optical networks. As Popular Science said: “Think of it as a miniature version of the Internet as it should be.”
“This award and accompanying recognition highlight how innovation can create mission value, two tenets of our IT strategy,” says Sandia Chief Information Officer Mike Vahle, VP of Information Technology Services
Div. 9000. “Additionally, it marks the culmination of many years of dedicated focus on bringing the promise of fiber optics to Sandia’s infrastructure. These types of innovations only become reality through the creativity and dedication of an outstanding team of people.”
Sandia needs superb computing capability for the nuclear weapons and national security research it does for NNSA. The Labs began looking at fiber optics early in the technology’s development because of its promise of greater communication speed at longer distances. So far, Sandia has converted more than 90 percent of its bulky copper cable because fiber offers far more capacity, is more secure and reliable, and is less expensive to maintain and operate than a traditional copper network.
In recognizing the non-detonable fertilizer, Popular Science said that in 2012 ammonium nitrate fertilizer was used in about 65 percent of the 16,300 improvised explosive devices found in Afghanistan. Sandia engineer Kevin Fleming, who retired earlier this year, developed a fertilizer that uses iron sulfite in the mixture to suppress detonation. He was assisted in the early stage research by Vicki Chavez (6633).
Sandia chose to keep the formula open-source so it could more quickly be adopted in developing countries.-- Sue Major Holmes