. | . |
Ancient micrometeoroids carried specks of stardust, water to asteroid 4 Vesta by Staff Writers St. Louis MO (SPX) Jun 10, 2020
The formation of our solar system was a messy affair. Most of the material that existed before its formation - material formed around other, long-dead stars - was vaporized, then recondensed into new materials. But some grains of that material, formed before the sun's birth, still persist. These "stardust" grains arrived on Earth inside primitive meteorites. New Washington University in St. Louis research led by Nan Liu, an assistant research professor in physics and the Laboratory for Space Sciences in Arts and Sciences, shows that stardust was also delivered to another planet-like body in the solar system, asteroid 4 Vesta, by micrometeoroids that also carried water. "Like our Earth," Liu said, "Vesta has a core, a mantle and crust," features that formed as the materials melted, differentiated and coalesced into a single planet-like object. And like Earth, Vesta is also pummeled by micrometeoroids. The brightest asteroid in the night sky, Vesta orbits the sun in the asteroid belt between Mars and Jupiter. Liu, along with Lionel Vacher, a postdoctoral researcher, and Ryan Ogliore, assistant professor of physics, studied samples of the Kapoeta meteorite for this research. Kapoeta fell to Earth in 1942 in what is now South Sudan, landing on a road in front of a British convoy during World War II. NASA's Dawn mission to asteroid Vesta established a link between Vesta and the howardites, eucrites and diogenites, groups of meteorites found on Earth. The research team focused on small, dark inclusions in Kapoeta that seemed out of place, like pieces of clay in lava rock. "They look completely different from surrounding material," Liu said. They turned out to be microscopic meteoroids, less than 100 microns across (smaller than the thickness of a human hair), that landed on Vesta's surface. Liu used the university's mass-spectrometer microscope, the NanoSIMS, to search the inclusions for presolar material. Because stardust has a very different isotopic composition from material that formed within the solar system, it jumped out at her under the microscope. The stardust in asteroid Vesta is a unique record of ancient, galactic material delivered long ago to a body far from Earth. The researchers postulate that the micrometeoroids arrived at Vesta after the violent impacts of the Late Heavy Bombardment, about 3.5 billion years ago. Vacher and Ogliore measured the chemical compositions of the micrometeoroids to understand in what type of environment they formed. They recognized minerals and textures that were linked to interactions between rock and water from melted ice.
One of the big questions is: How did water get on Earth? The ancient record of these micrometeoroids impacting Earth has been erased by weather and plate tectonics. The micrometeoroid record from asteroid Vesta may help to explain how water was delivered to the young Earth. "If icy micrometeoroids delivered water to the inner solar system when the Earth was still forming, this could be one way that the Earth ended up with enough water to support life," Ogliore said. "Habitable planets around other stars may have acquired their water through similar means." More analyses are needed to determine the when and the where. "Our next measurements will constrain when this wet material was delivered to Vesta, and where it came from: an icy asteroid, a comet or some other exotic source," Ogliore said.
Take a trip to 4 Vesta You can zoom in on Kapoeta thanks to Ryan Ogliore, assistant professor of physics. He worked to develop techniques to visualize objects from the micrometer to the millimeter scale - that's a factor of 1,000. "It's like he took a puzzle with 1,000 pieces, but Ryan is doing the same puzzle with 10,000 pieces," said Lionel Vacher, research assistant. Click here to visit the meteorite. The research was published in the journal Geochimica et Cosmochimica Acta.
Ancient asteroids helped synthesize life's molecular building blocks, study finds Washington DC (UPI) Jun 08, 2020 Before life began, Earth needed amino acids, the building blocks for proteins. New research suggests ancient asteroid impacts in Earth's primordial oceans could have produced the molecules needed to kick-start life. In the lab, scientists used a stage propellant gun to simulate the violent impact featuring water and a variety of organic chemicals, including carbon dioxide, nitrogen and iron. The experimental collisions yielded glycine and alanine, a pair of amino acids that form proteins ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |