Mystery of magnetized moon rocks revealed
Washington: A team of scientists at the University of California has shed light on the presence of magnetized rocks on the surface of the moon that has no global magnetic field, which has been a mystery since the days of the Apollo program.
They have proposed a novel mechanism that could have generated a magnetic field on the moon early in its history.
Christina Dwyer, a graduate student in Earth and planetary sciences at the University of California, Santa Cruz and her co-authors describe how an ancient lunar dynamo could have arisen from stirring of the moon’s liquid core driven by the motion of the solid mantle above it.
“This is a very different way of powering a dynamo that involves physical stirring, like stirring a bowl with a giant spoon,” Dwyer said.
At close distances, tidal interactions between the Earth and the moon caused the moon’s mantle to rotate slightly differently than the core. This differential motion of the mantle relative to the core stirred the liquid core, creating fluid motions that, in theory, could give rise to a magnetic dynamo.
“The moon wobbles a bit as it spins—that’s called precession--but the core is liquid, and it doesn’t do exactly the same precession. So the mantle is moving back and forth across the core, and that stirs up the core,” explained planetary scientists Francis Nimmo at UC Santa Cruz.
The researchers found that a lunar dynamo could have operated in this way for at least a billion years.
Eventually, however, it would have stopped working, as the moon got farther away from the Earth.
“The further out the moon moves, the slower the stirring, and at a certain point the lunar dynamo shuts off,” Dwyer said.
The study appeared in the Nov. 10 issue of Nature.
More from India
More from World
More from Sports
More from Entertaiment
- One year of Modi govt: PM promises to fulfil aspirations
- Watch: Mumbai cops find new secret agents in housewives!
- Hundreds die as heat wave continues in India
- 2G scam: Ex-TRAI chief alleges Manmohan Singh had warned him to cooperate
- Pranab Mukherjee defends Bofors scam, says it was just a media trial
- Salman Khan attends sister Arpita's wedding reception in Mandi
- Zee Media's mega survey on Modi govt
- Zee Media Exclusive: Vidya Balan chats about 'Hamari Adhuri Kahani'
- Para athlete Deepa Malik complains of callous service by Air India
- I eat beef, can somebody stop me?: Kiren Rijiju hits back at Naqvi
- Smriti Irani visits Amethi, promises to pay insurance money to 25,000 women
- Delhi: Visually impaired boy scores 91.4% in CBSE 12th Board exams
- One year of Modi govt: Amit Shah addresses media
- MP: 14-year-old boy works as bonded labour since 2009
- UP: Man chops off wife's nose, hair for dowry
- One year of NDA govt: PM Modi writes open letter to nation, promises to transform India
- Arpita-Aayush wedding reception: Salman Khan spreads love in Mandi, says `hum aapke hain`
- World optimistic about India: PM Narendra Modi on 1 year of NDA govt
- MSBSHSE Class 12th HSC results 2015 to be declared at 1pm tomorrow
- CBSE Class 10 Board Result 2015 (cbse.nic.in, cbseresults.nic.in) postponed?
- CBSE Class 10 Board Result 2015 to be announced on May 28
- Check mahresult.nic.in for MSBSHSE Maharashtra Class 12 HSC Result 2015
- Rahul Gandhi takes a dig at one year of Modi govt, wishes 'happy birthday' to 'suit-boot ki sarkar'
- Bharatiya Janata Party lacks majority for Ram Temple, Article 370: Amit Shah
- Maharashtra MSBSHSE HSC Result 2015 on mahresult.nic.in
- AAP govt moves resolution against MHA notification: As it happened
- I was misquoted, says Kiren Rijiju on 'beef' remark
- Heatwave kills 90 more in Andhra, Telangana; toll crosses 800
- Gujjars adamant on holding talks in Bayana; rail tracks remain blocked
- CBSE 10th result to be declared tomorrow