From The DOE’s Argonne National Laboratory: “Secrets from space:: Advanced Photon Source helps illuminate the journey of a 4 billion-year-old asteroid”

Argonne Lab

From The DOE’s Argonne National Laboratory

Andre Salles

A year ago, scientists got their first look at material gathered from nearby asteroid 162173 Ryugu. Now the results of those studies have been revealed, and they shed light on the history of our solar system and the long trek of this cosmic wanderer.

Argonne Distinguished Fellow Esen Ercan Alp, right, and physicist and group leader Jiyong Zhao, left, at APS Beamline 3-ID-B, where scientists measured the composition of fragments of a near-Earth asteroid. (Image by Jason Creps/Argonne National Laboratory.)

At its closest orbit, asteroid 162173 Ryugu is only about 60,000 miles from Earth. That’s only a quarter of the distance to the moon. But according to newly released results from an international team of scientists, this hunk of rock began its cosmic journey more than 4 billion years ago, and billions of miles away, in the outer part of our solar system. It traveled to us across space, taking in the history of this corner of the universe in the process.

These revelations are only part of the results of a global effort to study samples from the surface of Ryugu. These specks of asteroid dust were carefully collected and transported back to Earth by Hayabusa 2, a mission operated by the Japanese space agency JAXA, and then sent to institutions around the world.

Scientists put these tiny fragments through dozens of experiments to tease out their secrets, to determine what they are made of and how the asteroid they came from may have been formed.

The resulting paper, recently published in Science [below], includes authors from more than 100 institutions in 11 countries. Numbered among them is the U.S. Department of Energy’s (DOE) Argonne National Laboratory, home to the Advanced Photon Source [below], a DOE Office of Science user facility. The APS generates ultrabright X-ray beams that can be used to determine the chemical and structural makeup of samples atom by atom.

Argonne Distinguished Fellow Esen Ercan Alp led the research team at Argonne, which includes physicist and group leader Jiyong Zhao and physicist Michael Hu, and beamline scientist Barbara Lavina of both Argonne and the University of Chicago. All are co-authors on the paper.

Alp and his team worked for years to be included in this study. The key contribution of the APS, Alp said, is a particular X-ray technique he and his team specialize in. It’s called Mössbauer spectroscopy — named after German physicist Rudolf Mössbauer — and it is highly sensitive to tiny changes in the chemistry of samples. This technique allowed Alp and his team to determine the chemical composition of these fragments particle by particle.

UChicago and Argonne beamline scientist Barbara Lavina observes one of the tiny asteroid fragments through a microscope, with the magnified image on the screen beside her. (Image by Jason Creps/Argonne National Laboratory.)

What they and their international colleagues found was surprising, Alp said.

“There is enough evidence that Ryugu started in the outer solar system,” he said. ​“Asteroids found in the outer reaches of the solar system would have different characteristics than those found closer to the sun.”

The APS, Alp said, found several pieces of evidence to support this hypothesis. For one, the grains that make up the asteroid are much finer than you would expect if it was formed at higher temperatures. For another, the structure of the fragments is porous, which means it once held water and ice. Lower temperatures and ice are much more common in the outer solar system, Alp said.

The Ryugu fragments are very small — ranging from 400 microns, or the size of six human hairs, to 1 millimeter in diameter. But the X-ray beam used at beamline 3-ID-B can be focused down to 15 microns. The team was able to take several measurements on each of the fragments. They found the same porous, fine-grained structure across the samples.

With the APS’s finely tuned spectroscopy capabilities, the team was able to measure the amount of oxidation that the samples had undergone. This was especially interesting since the fragments themselves had never been exposed to oxygen — they were delivered in vacuum-sealed containers, in pristine condition from their trip across space.

While the APS team did find a chemical makeup similar to meteorites that have hit the Earth — specifically a group of them called CI chondrites, of which only nine are known to exist on the planet — they did discover something that set the Ryugu fragments apart.

Space Odyssey: Argonne scientists among the first to study asteroid fragments. (Video by JJ Starr.)

The spectroscopy measurements found a large amount of pyrrhotite, an iron sulfide that is nowhere to be found in the dozen meteorite samples the team also studied, courtesy of French collaborators Mathieu Roskosz (National Museum of Natural History) and Pierre Beck (Universite Grenoble Alpes). This result also helps scientists put a limit on the temperature and location of Ryugu’s parent asteroid at the time it was formed.

“Our results and those from other teams show that these asteroid samples are different from meteorites, particularly because meteorites have been through fiery atmosphere entry, weatherization and in particular oxidation on Earth,” said Hu. ​“This is exciting because it’s a completely different kind of sample, from way out in the solar system.”

With all of the data combined, the paper lays out the multi-billion-year history of 162173 Ryugu. It was once part of a much larger asteroid which formed about 2 million years after the solar system did — roughly 4.5 billion years ago. It was made of many different materials, including water and carbon dioxide ice, and over the next three million years, the ice melted. This led to an interior that was hydrated and surface that was dryer.

About a billion years ago, another chunk of space rock collided with this asteroid, breaking it apart and sending debris flying, and some of those fragments coalesced into the Ryugu asteroid we know today.

“For planetary scientists, this is first-degree information coming directly from the solar system, and hence it is invaluable,” Alp said.

The Argonne team plans their own paper, going into detail about their X-ray techniques and results. But being part of such a large, multi national scientific effort was thrilling, they said, and they look forward to being part of future experiments of this type.

“This was an exciting and challenging experience for us to participate in such a well-coordinated international research project.” Zhao said. ​“With an upgrade to the APS in the works that will deliver even brighter X-ray beams, we are anticipating studying more materials like this, from far-flung asteroids and planets.”

This project was funded in part by a grant from France and Chicago Collaborating in the Sciences (FACCTS), administered by the University of Chicago.

For more on this story, read the Japan Aerospace Exploration Agency press release here.

Science paper:

See the full article here .


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The DOE’s Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their is a science and engineering research national laboratory operated by UChicago Argonne LLC for the United States Department of Energy. The facility is located in Lemont, Illinois, outside of Chicago, and is the largest national laboratory by size and scope in the Midwest.

Argonne had its beginnings in the Metallurgical Laboratory of the University of Chicago, formed in part to carry out Enrico Fermi’s work on nuclear reactors for the Manhattan Project during World War II. After the war, it was designated as the first national laboratory in the United States on July 1, 1946. In the post-war era the lab focused primarily on non-weapon related nuclear physics, designing and building the first power-producing nuclear reactors, helping design the reactors used by the United States’ nuclear navy, and a wide variety of similar projects. In 1994, the lab’s nuclear mission ended, and today it maintains a broad portfolio in basic science research, energy storage and renewable energy, environmental sustainability, supercomputing, and national security.

UChicago Argonne, LLC, the operator of the laboratory, “brings together the expertise of the University of Chicago (the sole member of the LLC) with Jacobs Engineering Group Inc.” Argonne is a part of the expanding Illinois Technology and Research Corridor. Argonne formerly ran a smaller facility called Argonne National Laboratory-West (or simply Argonne-West) in Idaho next to the Idaho National Engineering and Environmental Laboratory. In 2005, the two Idaho-based laboratories merged to become the DOE’s Idaho National Laboratory.

What would become Argonne began in 1942 as the Metallurgical Laboratory at the University of Chicago, which had become part of the Manhattan Project. The Met Lab built Chicago Pile-1, the world’s first nuclear reactor, under the stands of the University of Chicago sports stadium. Considered unsafe, in 1943, CP-1 was reconstructed as CP-2, in what is today known as Red Gate Woods but was then the Argonne Forest of the Cook County Forest Preserve District near Palos Hills. The lab was named after the surrounding forest, which in turn was named after the Forest of Argonne in France where U.S. troops fought in World War I. Fermi’s pile was originally going to be constructed in the Argonne forest, and construction plans were set in motion, but a labor dispute brought the project to a halt. Since speed was paramount, the project was moved to the squash court under Stagg Field, the football stadium on the campus of the University of Chicago. Fermi told them that he was sure of his calculations, which said that it would not lead to a runaway reaction, which would have contaminated the city.

Other activities were added to Argonne over the next five years. On July 1, 1946, the “Metallurgical Laboratory” was formally re-chartered as Argonne National Laboratory for “cooperative research in nucleonics.” At the request of the U.S. Atomic Energy Commission, it began developing nuclear reactors for the nation’s peaceful nuclear energy program. In the late 1940s and early 1950s, the laboratory moved to a larger location in unincorporated DuPage County, Illinois and established a remote location in Idaho, called “Argonne-West,” to conduct further nuclear research.

In quick succession, the laboratory designed and built Chicago Pile 3 (1944), the world’s first heavy-water moderated reactor, and the Experimental Breeder Reactor I (Chicago Pile 4), built-in Idaho, which lit a string of four light bulbs with the world’s first nuclear-generated electricity in 1951. A complete list of the reactors designed and, in most cases, built and operated by Argonne can be viewed in the, Reactors Designed by Argonne page. The knowledge gained from the Argonne experiments conducted with these reactors 1) formed the foundation for the designs of most of the commercial reactors currently used throughout the world for electric power generation and 2) inform the current evolving designs of liquid-metal reactors for future commercial power stations.

Conducting classified research, the laboratory was heavily secured; all employees and visitors needed badges to pass a checkpoint, many of the buildings were classified, and the laboratory itself was fenced and guarded. Such alluring secrecy drew visitors both authorized—including King Leopold III of Belgium and Queen Frederica of Greece—and unauthorized. Shortly past 1 a.m. on February 6, 1951, Argonne guards discovered reporter Paul Harvey near the 10-foot (3.0 m) perimeter fence, his coat tangled in the barbed wire. Searching his car, guards found a previously prepared four-page broadcast detailing the saga of his unauthorized entrance into a classified “hot zone”. He was brought before a federal grand jury on charges of conspiracy to obtain information on national security and transmit it to the public, but was not indicted.

Not all nuclear technology went into developing reactors, however. While designing a scanner for reactor fuel elements in 1957, Argonne physicist William Nelson Beck put his own arm inside the scanner and obtained one of the first ultrasound images of the human body. Remote manipulators designed to handle radioactive materials laid the groundwork for more complex machines used to clean up contaminated areas, sealed laboratories or caves. In 1964, the “Janus” reactor opened to study the effects of neutron radiation on biological life, providing research for guidelines on safe exposure levels for workers at power plants, laboratories and hospitals. Scientists at Argonne pioneered a technique to analyze the moon’s surface using alpha radiation, which launched aboard the Surveyor 5 in 1967 and later analyzed lunar samples from the Apollo 11 mission.

In addition to nuclear work, the laboratory maintained a strong presence in the basic research of physics and chemistry. In 1955, Argonne chemists co-discovered the elements einsteinium and fermium, elements 99 and 100 in the periodic table. In 1962, laboratory chemists produced the first compound of the inert noble gas xenon, opening up a new field of chemical bonding research. In 1963, they discovered the hydrated electron.

High-energy physics made a leap forward when Argonne was chosen as the site of the 12.5 GeV Zero Gradient Synchrotron, a proton accelerator that opened in 1963. A bubble chamber allowed scientists to track the motions of subatomic particles as they zipped through the chamber; in 1970, they observed the neutrino in a hydrogen bubble chamber for the first time.

Meanwhile, the laboratory was also helping to design the reactor for the world’s first nuclear-powered submarine, the U.S.S. Nautilus, which steamed for more than 513,550 nautical miles (951,090 km). The next nuclear reactor model was Experimental Boiling Water Reactor, the forerunner of many modern nuclear plants, and Experimental Breeder Reactor II (EBR-II), which was sodium-cooled, and included a fuel recycling facility. EBR-II was later modified to test other reactor designs, including a fast-neutron reactor and, in 1982, the Integral Fast Reactor concept—a revolutionary design that reprocessed its own fuel, reduced its atomic waste and withstood safety tests of the same failures that triggered the Chernobyl and Three Mile Island disasters. In 1994, however, the U.S. Congress terminated funding for the bulk of Argonne’s nuclear programs.

Argonne moved to specialize in other areas, while capitalizing on its experience in physics, chemical sciences and metallurgy. In 1987, the laboratory was the first to successfully demonstrate a pioneering technique called plasma wakefield acceleration, which accelerates particles in much shorter distances than conventional accelerators. It also cultivated a strong battery research program.

Following a major push by then-director Alan Schriesheim, the laboratory was chosen as the site of the Advanced Photon Source, a major X-ray facility which was completed in 1995 and produced the brightest X-rays in the world at the time of its construction.

On 19 March 2019, it was reported in the Chicago Tribune that the laboratory was constructing the world’s most powerful supercomputer. Costing $500 million it will have the processing power of 1 quintillion flops. Applications will include the analysis of stars and improvements in the power grid.

With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science. For more visit

About the Advanced Photon Source

The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.

With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science. For more visit

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

Argonne Lab Campus