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Scientists dig for answers inside mineral-rich meteorites

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According to the scientists, neutron imaging is ideal for searching for water and other hydrogen-bearing compounds because neutrons readily ricochet off hydrogen. In contrast, X-ray imaging is best for finding deposits of heavy elements, such as iron and nickel, because X-rays are primarily scattered by the large number of electrons in heavy-weight atoms.

Neither imaging technique significantly harms or alters meteorites, unlike other methods of analyzing the chemical composition of the rocks, which require cutting thin slices of the meteorites. Although each imaging method has been used separately in the past, the team is among the first to use the two techniques simultaneously to create X-ray and neutron-beam snapshots.

In the pilot study, the group examined two meteorites whose mineral and water contents were already well known so that they could assess the accuracy of the combined imaging methods. One of the rocks, dubbed EET 87503, is a fragment from the surface of the large asteroid Vesta but also contains material from a different, water-rich variety of asteroid.

Movie of the meteorite EET 87503 depicts overlay of X-ray and neutron imaging. Purple and orange denote two different classes of iron-rich minerals; green denotes minerals that contain water in their structure. (Video courtesy of NIST).

The other meteorite, GRA 06100, rich in iron and nickel, is classified as a chondrite—a rock that has not been altered by melting or other processes since the early days of the solar system. It also has a significant amount of hydrogen-bearing silicates formed by past exposure to water.

To create three-dimensional views of the meteorites, the researchers used the X-ray and neutron beams to image cross-sections of the rocks. Individual images of different cross sections were then combined to create a 3D image, a technique known as tomography or CT scan.

The imaging methods accurately revealed the locations of metal-rich minerals, silicate minerals, water and other hydrogenated compounds in the two meteorites. Neutron imaging pinpointed and characterized the chondrite grains within GRA 06100, which could then be extracted for further study. The 3D imaging can test theories of how water entered the rock and what pathway the liquid took to alter the composition of minerals and become bound in the sample.

Although water accounts for 70% of earth’s surface, exactly how the substance arrived on our planet remains the subject of a longstanding debate. Some planetary scientists suggest that meteorites and comets—icy relics from the frigid, outer solar system—delivered the water, along with the building blocks of proteins essential for life, after our planet’s core had formed. Others suggest that earth acquired the water during its formation 4.5 billion years ago from bits of gas and dust that swaddled the infant sun and glommed together to form our planet.

Water comes in two forms: ordinary water, consisting of hydrogen and oxygen, and heavy water, consisting of deuterium (hydrogen with an added neutron) and oxygen. One way to determine if meteorites were a primary source of terrestrial water is to compare the relative abundance of these two types in the rocks to the relative abundance of the water on and beneath the earth’s surface. Planetary scientists have measured the abundance in some meteorites but need to examine a larger number.

The neutron and X-ray images can assist in these studies. By pinpointing the location of mineral, metal and water deposits locked inside meteorites, the images could guide researchers on how to best slice sections of the rocks so they can measure these abundances as well as the composition of other compounds.

Following this initial trial, the team now plans to use its dual imaging technique to study less familiar meteorites so that their water and mineral content can be mapped in detail for the first time.

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

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