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Rock on: Is your meteorite real?

ASU Center for Meteorite Studies is world’s largest university-based collection.
Public invited to bring in a rock to ASU to see if it's a meteorite Nov. 7.
Iron meteorites are "the core of a small planet," said ASU's Meenakshi Wadhwa.
Meteorites are finds or falls (seen falling). Falls are sexier in science world.
October 28, 2015

Public invited to Earth and Space Exploration Day at ASU to have specimens identified

The breathtaking possibility that they may have found an object that fell to Earth from millions of miles out in space will draw hundreds to the one-day-only meteorite-identification event at Arizona State University’s Earth and Space Exploration Day next month.

The crushing probability that it isn’t will be mollified by the opportunity to view the Meteorite Gallery’s spectacular collection at the annual event on Saturday, Nov. 7.

“Usually one or two turn out to be meteorites,” said Meenakshi Wadhwa, director of the Center for Meteorite Studies. “The probability that any one of them is a meteorite is pretty small.”

Her office voicemail states that the center does not identify potential meteorites on a regular basis.

Despite that, “I still get one or two messages every day asking if they can bring one in,” said Wadhwa, who is also a professor in ASU’s School of Earth and Space ExplorationThe School of Earth and Space Exploration is part of the College of Liberal Arts and Sciences..

The meteorite identification program was suspended five years ago because the center was swamped by requests.

“Most people don’t know what a meteorite is,” said research professor Laurence Garvie, collections manager of the Center for Meteorite Studies. “Not every heavy dark magnetic rock in the desert is a meteorite. It has to be slightly different in a particular kind of way. That’s the thing.”

ASU professor Meenakshi Wadhwa

Meenakshi Wadhwa, director of ASU's
Center for Meteorite Studies, shows
some of the hundreds of small stones
from the Chelyabinsk meteorite that
exploded over Russia on Feb. 15, 2013.

Photos by Charlie Leight/ASU Now

The desert Southwest is one of the better places to find meteorites because there’s not as much vegetation.

Meteorites fall into two categories: finds and falls. Both are named after where they were found, like Coolidge or Rancho Gomelia or Mayday.

A find is discovered on the ground. A fall is witnessed plummeting to Earth and then retrieved. Falls are much sexier in the meteorite world. The authoritative Meteoritical Bulletin carefully describes the circumstances of the discovery, noting such details as terrified cats and barns full of dust.

Meteorites can be tiny. The center possesses close to a kilogram of the famous Chelyabinsk meteorite, which was recorded by hundreds of cameras as it crashed into the Russian city on Feb. 15, 2013. That meteorite was the size of a Volkswagen bus. Before it shattered in the atmosphere, damaging more than 7,000 buildings and injuring more than 1,500 people, it weighed about 10,000 tons and traveled about 41,000 miles per hour.

“These things are continually hitting the Earth,” Wadhwa said. Fifty to 100 tons hit Earth every day.

Most are dust-size particles. “Meteor showers are not going to drop stuff,” Garvie said.

The center also owns a piece of broken window glass from Chelyabinsk. In the meteorite world, owning a piece of collateral damage as well as the meteorite itself is highly prized.

A meteorite is shown close up.
Meenakshi Wadhwa of the Center for Meteorite Studies displays a piece of the Allende meteorite, found in Mexico in 1969. She said the white sections are made of some of the oldest elements in the universe, dating back 4.56 billion years. The ASU center has about 2,000 different types of meteorites in its 40,000-specimen collection; it is the largest university-based collection in the world.

 

A 26-pound meteorite fell on Oct. 9, 1992, hitting the trunk of 18-year-old Michelle Knapp’s red 1980 Chevy Malibu in Peekskill, New York. The meteorite was still warm and smelling of sulfur when Knapp went out in the driveway to see what had happened. She sold the car — which she had just bought for $300 — to a meteorite collector’s wife for $10,000 and the meteorite for $69,000. The car has since traveled the world to museums and mineral shows.

Garvie pointed out there is not a black market in meteorites. “That’s a misconception,” he said.

When Wadhwa was curator at the Field Museum in Chicago, a meteorite shower hit the city. People called the police, thinking vandals were throwing rocks at their houses. The police confiscated many of the meteorites. “At the police station they were lined up like suspects,” she said.

Garvie holds out a specimen from Mars that was discovered in Morocco. Martian meteorites are the only materials from other planets ever recovered by humans. The ASU center has about 2,000 different types of meteorites in its 40,000-specimen collection; it’s the world’s largest university-based collection.

“We can learn a lot about planetary processes from them,” Wadhwa said. “That’s the core of a small planet you’re looking at there.”

“Let’s hope we get a meteorite this year,” she added.

Earth and Space Exploration Day

What: This annual event offers special science-related activities for students age 5 and up, families, educators and anyone interested in exploring Earth and space. In addition to the meteorite-identification event, there will be 3-D astronomy shows; special talks on volcanoes, earthquakes and planetary science; and interactive displays in the Gallery of Scientific Exploration. Visitors can also see a replica of the Curiosity Mars rover, explore "A" Mountain (Tempe Butte) on a guided field trip, bring rock samples for Dr. Rock to examine, and much more.

When: 9 a.m.-3 p.m. Saturday, Nov. 7.

Where: Interdisciplinary Science and Technology Building IV (ISTB 4) on Arizona State University’s Tempe campus. Find an interactive campus map here.

Admission: Free. Parking will be free as well.

Details: http://sese.asu.edu/earth-and-space-exploration-day. To register for the event, visit https://nasa.asu.edu/ESE-Day-Registration?destination=ESE-Day-Registration.

Chaos or collaboration?

ASU researcher looks at how humans learned to cooperate


October 28, 2015

How and why did human beings evolve to cooperate with unrelated individuals or even strangers? Consider National Public Radio — donors could listen for free, yet thousands of people donate, collectively supporting a public good.

To understand how this cooperative inclination developed in humans over the last millennia, scientists look to our primate cousins to see if they can observe glimmers of behavior that will help us understand the nature of human collective action. Chimpanzees, together with bonobos, are our closest living relatives, with whom we share at least 96 percent of our genome and a common ancestor that lived some five to seven million years ago. Ian Gilby Ian Gilby in the field. Download Full Image

ASU researcher Ian Gilby has been studying and observing chimpanzees in the wild since 1997. Gilby is an assistant professor in the School of Human Evolution and Social Change and a research affiliate with the Institute of Human Origins. He is also the codirector of the Jane Goodall Institute Research Center database that is the repository of detailed demographic and behavioral data on two communities of chimpanzees collected for over 70 years at Gombe National Park, Tanzania. Using these records and other long-term observational data from the Kibale Chimpanzee Project studying the Kanyawara chimpanzees of Kibale National Park, Uganda, Gilby and colleagues investigated the dynamics of chimpanzee group hunts of red colobus monkeys.

Chimpanzees hunting red colobus monkeys

In this study, which is the first to analyze hunting data from three chimpanzee communities, the researchers found that hunting was more likely to occur if certain key individuals were present when a chimpanzee group encountered red colobus monkeys. They hypothesized that these “impact hunters” catalyzed hunting by being the first to attack, thereby creating opportunities for others to catch prey in the ensuing chaos. Indeed, as predicted, impact hunters were more likely to hunt first than expected by chance, and importantly, affected long-term hunting patterns. At both Gombe and Kanyawara, overall hunting rates decreased after the death or “retirement” of impact hunters.

These results suggest that rather than hunting in a coordinated fashion, these chimpanzees follow an “every chimpanzee for himself” strategy. Hunting in groups is promoted because an individual’s selfish attempts to catch prey incidentally benefit others.

“These results are particularly exciting,” says Gilby, “because they demonstrate the importance of systematic individual differences for understanding the evolution of cooperation. The next step in our research is to investigate the source of this variation.”

"'Impact hunters’ catalyse cooperative hunting in two wild chimpanzee communities," written by Ian C. Gilby (Arizona State University), Zarin P. Machanda (Harvard University), Deus C. Mjungu (The Jane Goodall Institute, Gombe Stream Research Centre), Jeremiah Rosen (Harvard University), Martin N. Muller (University of New Mexico), Anne E. Pusey (Duke University) and Richard W. Wrangham (Harvard University) is published online in the Philosophical Transactions of the Royal Society B.

Julie Russ

Assistant director, Institute of Human Origins

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