Featured Research

from universities, journals, and other organizations

Magnesium oxide: From Earth to super-Earth

Date:
November 22, 2012
Source:
Carnegie Institution
Summary:
The mantles of Earth and other rocky planets are rich in magnesium and oxygen. Due to its simplicity, the mineral magnesium oxide is a good model for studying the nature of planetary interiors. New work studied how magnesium oxide behaves under the extreme conditions deep within planets and found evidence that alters our understanding of planetary evolution.

The mantles of Earth and other rocky planets are rich in magnesium and oxygen. Due to its simplicity, the mineral magnesium oxide is a good model for studying the nature of planetary interiors. New work from a team led by Carnegie's Stewart McWilliams studied how magnesium oxide behaves under the extreme conditions deep within planets and found evidence that alters our understanding of planetary evolution.

The research is published Nov. 22 by Science Express.

Magnesium oxide is particularly resistant to changes when under intense pressures and temperatures. Theoretical predictions claim that it has just three unique states with different structures and properties present under planetary conditions: solid under ambient conditions (such as on Earth's surface), liquid at high temperatures, and another structure of the solid at high pressure. The latter structure has never been observed in nature or in experiments.

McWilliams and his team observed magnesium oxide between pressures of about 3 million times normal atmospheric pressure (0.3 terapascals) to 14 million times atmospheric pressure (1.4 terapascals) and at temperatures reaching as high as 90,000 degrees Fahrenheit (50,000 Kelvin), conditions that range from those at the center of our Earth to those of large exo-planet super-Earths. Their observations indicate substantial changes in molecular bonding as the magnesium oxide responds to these various conditions, including a transformation to a new high-pressure solid phase.

In fact, when melting, there are signs that magnesium oxide changes from an electrically insulating material like quartz (meaning that electrons do not flow easily) to a metal similar to iron (meaning that electrons do flow easily through the material).

Drawing from these and other recent observations, the team concluded that while magnesium oxide is solid and non-conductive under conditions found on Earth in the present day, the early Earth's magma ocean might have been able to generate a magnetic field. Likewise, the metallic, liquid phase of magnesium oxide can exist today in the deep mantles of super-Earth planets, as can the newly observed solid phase.

"Our findings blur the line between traditional definitions of mantle and core material and provide a path for understanding how young or hot planets can generate and sustain magnetic fields," McWilliams said.

"This pioneering study takes advantage of new laser techniques to explore the nature of the materials that comprise the wide array of planets being discovered outside of our Solar System," said Russell Hemley, director of Carnegie's Geophysical Laboratory. "These methods allow investigations of the behavior of these materials at pressures and temperatures never before explored experimentally."


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Cite This Page:

Carnegie Institution. "Magnesium oxide: From Earth to super-Earth." ScienceDaily. ScienceDaily, 22 November 2012. <www.sciencedaily.com/releases/2012/11/121122152949.htm>.
Carnegie Institution. (2012, November 22). Magnesium oxide: From Earth to super-Earth. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2012/11/121122152949.htm
Carnegie Institution. "Magnesium oxide: From Earth to super-Earth." ScienceDaily. www.sciencedaily.com/releases/2012/11/121122152949.htm (accessed April 23, 2014).

Share This



More Earth & Climate News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California Drought Is Good News for Gold Prospectors

California Drought Is Good News for Gold Prospectors

AFP (Apr. 22, 2014) — For months California has suffered from a historic drought. The lack of water is worrying for farmers and ranchers, but for gold diggers it’s a stroke of good fortune. With water levels low, normally inaccessible areas are exposed. Duration: 01:57 Video provided by AFP
Powered by NewsLook.com
Raw: MN Lakes Still Frozen Before Fishing Opener

Raw: MN Lakes Still Frozen Before Fishing Opener

AP (Apr. 22, 2014) — With only three weeks until Minnesota's fishing opener, many are wondering if the ice will be gone. Some of the Northland lakes are still covered by up to three feet of ice, causing concern that just like last year, the lakes won't be ready. (April 22) Video provided by AP
Powered by NewsLook.com
Scientists Warn Of Likely El Niño Event This Year

Scientists Warn Of Likely El Niño Event This Year

Newsy (Apr. 22, 2014) — With Pacific ocean water already showing signs of warming, the NOAA says there's about a 66 percent chance the event will begin before November. Video provided by Newsy
Powered by NewsLook.com
Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) — South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
 
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins