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New Timeline Established for Ancient Magnetic Field on Mars – Lab Manager Magazine

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Mars had a global magnetic field much earlier—and much later—in the planet’s history than scientists have previously known.

A planet’s global magnetic field arises from what scientists call a dynamo: a flow of molten metal within the planet’s core that produces an electrical current. On Earth, the dynamo is what makes compass needles point north. But Mars’ dynamo has been extinct for billions of years.

New findings from University of British Columbia (UBC) researchers working with colleagues in the US and France, published May 1 in Science Advances, bring us closer to knowing the precise timing and duration of Mars’ dynamo.

“We find that the Martian dynamo operated at 4.5 billion and 3.7 billion years ago. Dynamo timing is a big part of a planet’s evolution, and what we find is very different from what we have thought so far,” said Anna Mittelholz, postdoctoral fellow in UBC’s Department of Earth, Ocean and Atmospheric Sciences, and first author of the study. “The dynamo tells us something about the planet’s thermal history, its evolution, and how it got to where it is today, and it is unique for each of the terrestrial planets—Earth, Mars, Venus, and Mercury.”

Clues about a planet’s magnetic history lie in magnetized rocks on and beneath its surface. Rock is like a tape recorder, especially volcanic rocks. They begin as lava, but as they cool and solidify in the presence of a magnetic field, minerals within the rocks align themselves with the global magnetic field. By dating these rocks, scientists can estimate if a dynamo was active at the time the rock was emplaced.

Magnetism in certain rocks on Mars’ surface indicate that the Martian dynamo was active between 4.3 and 4.2 billion years ago, but the absence of magnetism over three large basins that formed 3.9 billion years ago has led most scientists to believe the dynamo was inactive by that time.


Related Article: Promising Signs of Past Martian Life at Jezero Crater 


The UBC researchers analyzed new satellite data and found clear evidence of a magnetic field coming from the Lucus Planum lava flow that formed less than 3.7 billion years ago—much later than the aforementioned basins.

The researchers also detected low-intensity magnetic fields over the Borealis Basin in the planet’s northern hemisphere, which formed 4.5 billion years ago and is believed to be one of the oldest features on Mars.

“We have these two observations that point to a dynamo at the earliest known time in Mars’ history, and a dynamo that was present half a billion years after many people thought it had already switched off,” said Catherine Johnson, a professor in the Department of Earth, Ocean and Atmospheric Sciences and senior scientist at the Planetary Science Institute in Tucson, AZ, who also contributed to the study.

The researchers offer two possible explanations for the absence of magnetic fields over the basins: the dynamo may have stopped before the basins formed and then re-started before Lucus Planum formed, or the impacts that created the basins simply displaced the portion of crust containing minerals that can carry strong magnetism.

The new data for this study come from MAVEN, the Mars Atmosphere and Volatile Evolution satellite. Earlier data about magnetism on Mars had been gathered by the Mars Global Surveyor satellite which orbited the planet between 1999 and 2006, mostly at 400 kilometers above the surface. MAVEN, launched in 2013, operates as close as ~135 kilometers from the surface and picks up weaker signals that MGS could not detect.

MAVEN’s ability to pick up signals from smaller features on and near the surface helps researchers distinguish whether the magnetism is coming from those, or from older rocks buried more deeply in the planet’s crust.

These new insights have researchers wondering what could be revealed if they get even closer. Mittelholz noted that this study focused on two particular features, but craters remain all over Mars with stories to tell. In the future, exploration could progress from satellites to drones or balloons, providing even more detailed data.

This press release was originally published on the UBC News website

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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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