The thousands of samples of dust, gathered from the Stardust mission, tell a story of a comet that formed in the Kuiper Belt, outside the orbit of Neptune, and only recently entered the inner regions of the solar system.
Wild 2 spent most of its life orbiting in the Kuiper Belt, far beyond Neptune, and in 1974 had a close encounter with Jupiter that placed it into its current orbit. The Stardust spacecraft’s seven-year mission returned to earth earlier this year with particles that are the same material that accreted along with ice to shape the comet about 4.57 billion years ago, when the sun and planets formed.
But during its lifetime, Wild 2 gathered material that formed much closer to the sun.
"We’re talking about a mineral that forms around 3,000 degrees Kelvin, which means it formed close to the hot infant star," said John Bradley, director of the Laboratory’s Institute for Geophysics and Planetary Physics and the head of the Livermore Stardust team. "If we found it in the comet, then how the heck did it get out there""
The mineral in question is osbornite, which only has been found on earth in Russia.
More than 200 investigators worldwide including researchers from Lawrence Livermore will publish several papers in a series of analyses of the space dust in the Dec. 15 issue of the journal Science.
By using state-of-the-art technology, scientists from Lawrence Livermore National Laboratory have been able to determine the make-up of the tiny particles at the angstrom scale using the SuperSTEM (scanning transmission electron microscope).
The osbornite finding is an indication that during its infancy, the solar system was a very volatile locale in which objects in the inner area may have been ejected in bipolar outflows perpendicular to the solar accretion disc and rained down into the outer regions.
"It appears to have been a much more dynamic and perhaps even violent nebula environment than we expected," Bradley said.
And it is this mixing of the solar system that initially had scientists scratching their heads. In addition to outer solar system materials, the comet samples also contain pre-solar materials that in turn mean they must have been transported beyond the orbit of Neptune by a process that was capable of moving particles at least as large as 20 microns (a micron is 10 times smaller than a human hair).
The osbornite discovery supports the theory that large particles could be launched by a type of wind from a region within a few radii of the young sun and ballistically be transported above and below the midplane of the nebular disk. This wind model would transport these hot-formed particles from near the sun to the edge of the solar system where Wild 2 formed.
Most of the particles larger than a micron are made up of the silicate minerals olivine and pyroxene, also minerals that form at very high temperatures.
"It’s shaking up our view of the solar system condensation process," said Hope Ishii, one of the Livermore Stardust researchers. "It’s been pretty intense. It opens up a whole bunch of new questions."
In addition to the SuperSTEM, Livermore researchers used the Laboratory’s secondary electron microscope, nanoSIMS and Focused Ion Beam (FIB) technology to analyze the dust particles. Using the FIB, Livermore researchers Giles Graham and Nick Teslich were the first scientists to detect the craters containing miniscule particles in the collector foil. The foils contained the only examples found thus far of presolar material.
In addition to silicates and sulfides, Stardust samples contain organic materials dispersed around the impacts.
"We didn’t expect any organics to survive" from the impact and heat during the collection process, said Livermore researcher Sasa Bajt. "But we found a rich variety of organics that were both oxygen-rich and nitrogen rich compared to organics previously found in meteorites."
And those organics could point to the beginnings of life on Earth.
Stardust is a part of NASA’s series of Discovery missions and is managed by the Jet Propulsion Laboratory. Stardust launched in February 1999 and set off on three giant loops around the sun. It began collecting interstellar dust in 2000 and met Wild 2 in January 2004, when the spacecraft was slammed by millions of comet particles, nearly halting the mission. It is the first spacecraft to safely make it back to Earth with cometary dust particles in tow.
Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland
Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences