Featured Research

from universities, journals, and other organizations

New clues to the early solar system from ancient meteorites

Date:
July 22, 2012
Source:
Carnegie Institution
Summary:
In order to understand Earth's earliest history -- its formation from solar system material into the present-day layering of metal core and mantle, and crust -- scientists look to meteorites. New research focuses on one particularly old type of meteorite called diogenites. These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the solar system's earliest chemical processing.

Artist's concept of an early solar system forming.
Credit: NASA/JPL-Caltech

In order to understand Earth's earliest history--its formation from Solar System material into the present-day layering of metal core and mantle, and crust--scientists look to meteorites. New research from a team including Carnegie's Doug Rumble and Liping Qin focuses on one particularly old type of meteorite called diogenites. These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the Solar System's earliest chemical processing.

Related Articles


Their work is published online July 22 by Nature Geoscience.

At some point after terrestrial planets or large bodies accreted from surrounding Solar System material, they differentiate into a metallic core, asilicate mantle, and a crust. This involved a great deal of heating. The sources of this heat are the decay of short-lived radioisotopes, the energy conversion that occurs when dense metals are physically separated from lighter silicate, and the impact of large objects. Studies indicate that the Earth's and Moon's mantles may have formed more than 4.4 billion years ago, and Mars's more than 4.5 billion years ago.

Theoretically, when a planet or large body differentiates enough to form a core, certain elements including osmium, iridium, ruthenium, platinum, palladium, and rhenium -- known as highly siderophile elements -- are segregated into the core. But studies show that mantles of Earth, Moon and Mars contain more of these elements than they should. Scientists have several theories about why this is the case and the research team -- which included lead author James Day of Scripps Institution of Oceanography and Richard Walker of the University of Maryland -- set out to explore these theories by looking at diogenite meteorites.

Diogenites are a kind of meteorite that may have come from the asteroid Vesta, or a similar body. They represent some of the Solar System's oldest existing examples of heat-related chemical processing. What's more, Vesta or their other parent bodies were large enough to have undergone a similar degree of differentiation to Earth, thus forming a kind of scale model of a terrestrial planet.

The team examined seven diogenites from Antarctica and two that landed in the African desert. They were able to confirm that these samples came from no fewer than two parent bodies and that the crystallization of their minerals occurred about 4.6 billion years ago, only 2 million years after condensation of the oldest solids in the Solar System.

Examination of the samples determined that the highly siderophile elements present in the diogenite meteorites were present during formation of the rocks, which could only occur if late addition or 'accretion' of these elements after core formation had taken place. This timing of late accretion is earlier than previously thought, and much earlier than similar processes are thought to have occurred on Earth, Mars, or the Moon.

Remarkably, these results demonstrate that accretion, core formation, primary differentiation, and late accretion were all accomplished in just over 2 to 3 million years on some parent bodies. In the case of Earth, there followed crust formation, the development of an atmosphere, and plate tectonics, among other geologic processes, so the evidence for this early period is no longer preserved.

"This new understanding of diogenites gives us a better picture of the earliest days of our Solar System and will help us understand the Earth's birth and infancy," Rumble said. "Clearly we can now see that early events in planetary formation set the stage very quickly for protracted subsequent histories."

This work was supported by NASA.


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. "New clues to the early solar system from ancient meteorites." ScienceDaily. ScienceDaily, 22 July 2012. <www.sciencedaily.com/releases/2012/07/120722135204.htm>.
Carnegie Institution. (2012, July 22). New clues to the early solar system from ancient meteorites. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2012/07/120722135204.htm
Carnegie Institution. "New clues to the early solar system from ancient meteorites." ScienceDaily. www.sciencedaily.com/releases/2012/07/120722135204.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Space & Time News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Soyuz Spacecraft Docks With International Space Station: NASA

Soyuz Spacecraft Docks With International Space Station: NASA

AFP (Nov. 24, 2014) A Russian Soyuz spacecraft carrying Italy's first female astronaut safely docks with the International Space Station, according to NASA. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Multi-National Crew Safely Docks at Space Station

Multi-National Crew Safely Docks at Space Station

Reuters - US Online Video (Nov. 24, 2014) A Russian Soyuz rocket delivers a multi-national trio to the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Raw: Soyuz Docks With Int'l Space Station

Raw: Soyuz Docks With Int'l Space Station

AP (Nov. 23, 2014) A Russian capsule carrying three astronauts from Russia, the United States and Italy has arrived at the International Space Station. (Nov. 23) Video provided by AP
Powered by NewsLook.com
Raw: Crew Blasts Off for Int'l Space Station

Raw: Crew Blasts Off for Int'l Space Station

AP (Nov. 23, 2014) A Russian capsule carrying three astronauts from Russia, the United States and Italy has blasted off for the International Space Station. (Nov. 23) Video provided by AP
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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