Mystery of Moon’s Magnetic Field Deepens
By Charles Q. Choi | SPACE
The moon generated a surprisingly intense magnetic field until at least 3.56 billion years ago, 160 million years longer than previously thought, a new study reports.
These findings could shed light not just on the magnetic field of the moon, which is now extremely weak, but on that of asteroids and other distant worlds, investigators added.
Earth’s magnetic field is created by its internal dynamo, which itself is generated by the planet’s churning molten metal core. Research increasingly suggests that the moon once had a dynamo as well, with evidence of magnetism found in lunar rocks returned by Apollo astronauts.
Models of the moon’s core suggest its dynamo should have lasted only until about 4.1 billion years ago. However, last year, scientists revealed that the moon possessed a magnetic field for much longer than previously thought, with a powerful dynamo in its core from 4.2 billion years ago to at least 3.72 billion years ago.
Researchers have proposed two possibilities to explain why the moon’s dynamo lasted so long. One possible explanation is that giant cosmic impacts set the moon lurching enough to drive its dynamo. Another explanation has to do with how the moon’s core spins around a slightly different axis than its surrounding mantle layer, generating wobbles — known as precession — that could dramatically stir its core.
The cosmic-impact idea is supported by the fact that the moon experienced massive collisions until around 3.7 billion years ago, such as the one that created the 715-mile-wide (1,150 kilometers) Mare Imbrium, among other craters.
However, the dynamo generated by each impact would have lasted for a mere 10,000 years or so, scientists say. In contrast, if precession drove a lunar dynamo, the moon could have continuously possessed a magnetic field until as late as 1.8 billion years ago.
Now, a new analysis of the biggest lunar rock brought back to Earth by Apollo 11 astronauts in 1969 reveals the moon’s dynamo lasted about 160 million years longer than previously thought, well after the last of the largest crater-forming impacts hit the moon.
Read the full article at: space.com
Big Bang: Biggest meteorite explosion rocks the Moon
Do We Really Need the Moon? - BBC Documentary
Water on Earth and Moon May Have Same Source
What If We Lost Our Moon?
Latest News from our Front Page
Estonia must accept African & Middle Eastern immigrants says politician
Kalle Laanet, an Estonian politician, spoke at the International Migration Forum held in Tallinn. He told the audience that the question is not: Should Estonia take the African and the Middle Eastern immigrants (who illegally entered Southern Europe)? He said the question is: How will Estonia take the immigrants?
â€œToday the issue is not whether Estonia should receive the refugees coming to ...
Rescuing Palmyra: History's lesson in how to save artefacts
With Islamic State militants now inside the historic town of Palmyra in Syria, the question, inevitably, is whether they will destroy the ancient ruins.
As IS continues to sweep through parts of Iraq and Syria, damage to centuries-old artefacts - because IS sees statues and shrines as idolatrous - is plentiful.
But history has shown that, when culturally important sites are under ...
Saudi Arabia Wants to Convert Sweden to Islam
Aje Carlbom is an Associate Professor of Social Anthropology, University of Malmö
Since the 1970s, Saudi Arabia has actively spread its interpretation of Islam, Wahhabism or Salafism, worldwide. It is the most literal version of Islam and affects many young Muslims, who regard society as a place to Islamize, writes social anthropologist Aje Carlbom.
Sweden's Foreign Minister Margot WallstrÃ¶m was ...
Professor: If You Read To Your Kids, You're 'Unfairly Disadvantaging' Others
According to a professor at the University of Warwick in England, parents who read to their kids should be thinking about how they're "unfairly disadvantaging other people's children" by doing so.
In an interview with ABC Radio last week, philosopher and professor Adam Swift said that since "bedtime stories activities . . . do indeed foster and produce . . ...
If You Read About Conspiracies You're Just Like Osama Bin Laden Apparently
At its heart, the story of Osama bin Laden's time at his house in Abbottabad is surreal. The American image of bin Laden - leering at us from under his head wrap as he plots and schemes - is undermined by the mundane realities of his life. The guy was responsible for murdering thousands of Americans and orchestrating a global ...
|More News » |