Published in the January 8 issue of the journal Nature, this is the first ever finding of material from an asteroid with a crust like Earth's. The discovery also represents the oldest example of rock with this composition ever found.
These meteorites point "to previously unrecognized diversity” of materials formed early in the history of the Solar System, write authors James Day, Richard Ash, Jeremy Bellucci, William McDonough and Richard Walker of the University of Maryland; Yang Liu and Lawrence Taylor of the University of Tennessee and Douglas Rumble III of the Carnegie Institution for Science.
"What is most unusual about these rocks is that they have compositions similar to Earth's andesite continental crust -- what the rock beneath our feet is made of,” said first author Day, who is a research scientist in Maryland's department of geology. "No meteorites like this have ever been seen before.”
Day explained that his team focused their investigations on how such different Solar System bodies could have crusts with such similar compositions. "We show that this occurred because of limited melting of the asteroid, and thus illustrate that the formation of andesite crust has occurred in our solar system by processes other than plate tectonics, which is the generally accepted process that created the crust of Earth”.
The two meteorites (numbered GRA 06128 and GRA 06129) were discovered in the Graves Nunatak Icefield during the US Antarctic Search for Meteorites 2006/2007 field season. Day and his colleagues immediately recognized that these meteorites were unusual because of elevated contents of a light-colored feldspar mineral called oligoclase. "Our age results point to these rocks being over 4.52 billion years old and that they formed during the birth of the Solar System. Combined with the oxygen isotope data, this age points to their origin from an asteroid rather than a planet,” he said.Andesite Asteroids
According to Day and his colleagues, finding pieces of meteorites with andesite compositions is important because they not only point to a previously unrecognized diversity of Solar System materials, but also to a new mechanism to generate andesite crust. On the present-day Earth, this occurs dominantly through plates colliding and subduction – where one plate slides beneath another. Subduction forces water back into the mantle aiding melting and generating arc volcanoes, such as the Pacific Rim of Fire – in this way new crust is formed.
"Our studies of the GRA meteorites suggest similar crust compositions may be formed via melting of materials in planets that are initially volatile- and possibly water-rich, like the Earth probably was when if first formed” said Day.” A major uncertainty is how evolved crust formed in the early Solar System and these meteorites are a piece in the puzzle to understanding these processes.”
This research was supported by NASA's cosmochemistry program.
Lee Tune | Newswise Science News
Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union
UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences