PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Scientists solve mystery of odd patterns of oxygen in solar system's earliest rocks

Reaction replicates formation of first silicate dust; oxygen isotopes match mix seen in stony meteorites

2013-10-25
(Press-News.org) Contact information: Susan Brown
sdbrown@ucsd.edu
858-246-0161
University of California - San Diego
Scientists solve mystery of odd patterns of oxygen in solar system's earliest rocks Reaction replicates formation of first silicate dust; oxygen isotopes match mix seen in stony meteorites Cosmochemists have solved a long standing mystery in the formation of the solar system: Oxygen, the most abundant element in Earth's crust, follows a strange, anomalous pattern in the oldest, most pristine rocks, one that must result from a different chemical process than the well-understood reactions that form minerals containing oxygen on Earth.

"Whatever the source of the anomaly must be a major process in the formation of the solar system, but it has remained a matter of contention," said Mark Thiemens, dean of the University of California, San Diego's division of physical sciences and professor of chemistry. "Our experiments essentially recreate the early solar system in that they take gas phase molecules and make a solid, a silicate that is essentially the building block of planets."

By re-creating conditions in the solar nebula, the swirl of gas that coalesced to form our star, the planets and the remnant rocky debris that circles the Sun as asteroids, the researchers demonstrated that a simple chemical reaction, governed by known physical principles, can generate silicate dust with oxygen anomalies that match those found in the oldest rocks in the solar system, they report in the early online edition of Science October 24.

Scientists first noted the discrepancy forty years ago in a stony meteorite that exploded over Pueblito de Allende, Mexico, and it has been confirmed in other meteorites as well. These stony meteorites, asteroids that fell to Earth, are some of the oldest objects in the solar system, believed to have formed nearly 4.6 billion years ago with the solar nebula's first million years. The mix between oxygen-16, the most abundant form with one neutron for each proton, and variants with an extra neutron or two, is strikingly different from that seen in terrestrial rocks from Earth, its moon and Mars.

"Oxygen isotopes in meteorites are hugely different from those of the terrestrial planets," said Subrata Chakraborty, a project scientist in chemistry at UC San Diego and the lead author of the report. "With oxygen being the third most abundant element in the universe and one of the major rock forming elements, this variation among different solar system bodies is a puzzle that must be solved to understand how the solar system formed and evolved,"

Oxygen isotopes usually sort out according to mass: oxygen-17, with just one extra neutron, is incorporated into molecules half as often as oxygen-18, with two extra neutrons. In these stony meteorites though, the two heavier oxygen isotopes show up in equal proportions. The rates at which they are incorporated into minerals forming these earliest rocks was independent of their masses. Thiemens and John Heidenreich demonstrated such mass-independent fractionation of oxygen isotopes in the formation of ozone thirty years ago, but the mechanism for a similar process in forming the solid building blocks of rocks has not be demonstrated experimentally before now.

Indeed, several competing ideas have been put forth as potential explanations for the anomaly. Some have suggested that the mix of oxygen isotopes was different back when the earliest solid matter in the solar system formed, perhaps enriched by matter blasted in from a nearby supernova. Others had proposed a photochemical effect called self-shielding, which this team has previously ruled out. The last-standing idea was that a physical chemical principle called symmetry could account for the observed patterns of oxygen isotopes.

To test that idea, Chakraborty filled a hockey puck sized chamber with pure oxygen, varying amounts of pure hydrogen and a little black nugget of solid silicon monoxide. He used a laser to vaporize a plume of silicon monoxide gas into the mix. These are ingredients seen by radiotelescopes in instellar clouds, the starting point for our solar system.

The silicon monoxide gas reacted with the oxygen and hydrogen to form silicon dioxide, a solid that settled as dust in the chamber and is the basis of silicate minerals like quartz that are so prevalent in the crust of the Earth. These reactions of gases formed the earliest solid materials in the solar system.

When Chakraborty and Petia Yanchulova, a physics student and co-author of the paper, collected and analyzed the dust, they saw a mix of oxygen isotopes that matched the anomalous pattern found in stony meteorites. The degree of the anomaly scaled with the percentage of the atmosphere that was hydrogen, an observation that points to a reaction governed by symmetry.

"No mattter what else happened early on in the nebula, this is the last step in making the first rocks from scratch," Thiemens said. "We've shown that you don't need a magic recipe to generate this oxygen anomaly. It's just a simple feature of physical chemistry."

INFORMATION:

NASA's Cosmochemistry and Origins of Solar Systems programs funded this work.

END



ELSE PRESS RELEASES FROM THIS DATE:

Increasing toxicity of algal blooms tied to nutrient enrichment and climate change

2013-10-25
Increasing toxicity of algal blooms tied to nutrient enrichment and climate change CORVALLIS, Ore. – Nutrient enrichment and climate change are posing yet another concern of growing importance: an apparent increase in the toxicity of some algal blooms in freshwater ...

Unique chemistry in hydrogen catalysts

2013-10-25
Unique chemistry in hydrogen catalysts Making hydrogen easily and cheaply is a dream goal for clean, sustainable energy. Bacteria have been doing exactly that for billions of years, and now chemists at the University of California, Davis, and Stanford University ...

Yeast, human stem cells drive discovery of new Parkinson's disease drug targets

2013-10-25
Yeast, human stem cells drive discovery of new Parkinson's disease drug targets CAMBRIDGE, Mass. (October 24, 2013) – Using a discovery platform whose components range from yeast cells to human stem cells, Whitehead Institute scientists have identified ...

A thermoelectric materials emulator

2013-10-25
A thermoelectric materials emulator Behavior of thermoelectric materials simulated Discovered in the 19th century, thermoelectric materials have the remarkable property that heating them creates a small electrical current. But enhancing this current to a level ...

Exercise during pregnancy improves vascular function of offspring into adulthood

2013-10-25
Exercise during pregnancy improves vascular function of offspring into adulthood Exercise during gestation has the potential to program vascular health in offspring into their adulthood, in particular significantly altering the vascular smooth muscle, shows a new study published ...

Persuading light to mix it up with matter

2013-10-25
Persuading light to mix it up with matter CAMBRIDGE, MA -- Researchers at MIT have succeeded in producing and measuring a coupling of photons and electrons on the surface of an unusual type of material called a topological insulator. This type of coupling ...

UMass Amherst polymer scientists jam nanoparticles, trapping liquids in useful shapes

2013-10-25
UMass Amherst polymer scientists jam nanoparticles, trapping liquids in useful shapes The advance holds promise for a wide range of different applications including in drug delivery, biosensing, fluidics, photovoltaics, encapsulation and bicontinuous ...

Genetic analysis reveals insights into the genetic architecture of OCD, Tourette syndrome

2013-10-25
Genetic analysis reveals insights into the genetic architecture of OCD, Tourette syndrome An international research consortium led by investigators at Massachusetts General Hospital (MGH) and the University of Chicago has answered several questions about ...

What is it about your face?

2013-10-25
What is it about your face? Berkeley Lab researchers provide new insight into why each human face is unique The human face is as unique as a fingerprint, no one else looks exactly like you. But what is it that makes facial morphology so distinct? Certainly ...

Why plants usually live longer then animals

2013-10-25
Why plants usually live longer then animals Ghent, 24 October –Stem cells are crucial for the continuous generation of new cells. Although the importance of stem cells in fuelling plant growth and development still many questions on their tight molecular ...

LAST 30 PRESS RELEASES:

CMD-OPT model enables the discovery of a potent and selective RIPK2 inhibitor as preclinical candidate for the treatment of acute liver injury

Melatonin receptor 1a alleviates sleep fragmentation-aggravated testicular injury in T2DM by suppression of TAB1/TAK1 complex through FGFR1

Single-cell RNA sequencing reveals Shen-Bai-Jie-Du decoction retards colorectal tumorigenesis by regulating the TMEM131–TNF signaling pathway-mediated differentiation of immunosuppressive dendritic ce

Acta Pharmaceutica Sinica B Volume 15, Issue 7 Publishes

New research expands laser technology

Targeted radiation offers promise in patients with metastasized small cell lung cancer to the brain

A high clinically translatable strategy to anti-aging using hyaluronic acid and silk fibroin co-crosslinked hydrogels as dermal regenerative fillers

Mount Sinai researchers uncover differences in how males and females change their mind when reflecting on past mistakes

CTE and normal aging are difficult to distinguish, new study finds

Molecular arms race: How the genome defends itself against internal enemies

Tiny chip speeds up antibody mapping for faster vaccine design

KTU experts reveal why cultural heritage is important for community unity

More misfolded proteins than previously known may contribute to Alzheimer’s and dementia

“Too much going on”: Autistic adults overwhelmed by non-verbal social cues

What’s driving America’s deep freezes in a warming world?

A key role of brain protein in learning and memory is deciphered by scientists

Heart attacks don’t follow a Hollywood script

Erin M. Schuman wins 2026 Nakasone Award for discovery on neural synapse function and change during formation of memories

Global ocean analysis could replace costly in-situ sound speed profiles in seafloor positioning, study finds

Power in numbers: Small group professional coaching reduces rates of physician burnout by nearly 30%

Carbon capture, utilization, and storage: A comprehensive review of CCUS-EOR

New high-temperature stable dispersed particle gel for enhanced profile control in CCUS applications

State gun laws and firearm-related homicides and suicides

Use of tobacco and cannabis following state-level cannabis legalization

Long-term obesity and biological aging in young adults

Eindhoven University of Technology and JMIR Publications announce unlimited open access publishing agreement

Orphan nuclear receptors in metabolic dysfunction-associated steatotic liver disease development

A technological breakthrough for ultra-fast and greener AI

Pusan National University researchers identify key barriers hindering data-driven smart manufacturing adoption

Inking heterometallic nanosheets: A scalable breakthrough for coating, electronics, and electrocatalyst applications

[Press-News.org] Scientists solve mystery of odd patterns of oxygen in solar system's earliest rocks
Reaction replicates formation of first silicate dust; oxygen isotopes match mix seen in stony meteorites