Space

NASA creates artificial stardust

NASA creates artificial stardust
Scanning Electron Microscope image of average nanograins produced in the COSmIC (Image: NASA/Ames/Farid Salama)
Scanning Electron Microscope image of average nanograins produced in the COSmIC (Image: NASA/Ames/Farid Salama)
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Scanning Electron Microscope image of a large aggregate of nanograins produced in the Cosmic Simulation Chamber (Image: NASA/Ames/Farid Salama)
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Scanning Electron Microscope image of a large aggregate of nanograins produced in the Cosmic Simulation Chamber (Image: NASA/Ames/Farid Salama)
Scientists will use the new capability to study the formation of interstellar grains in the outflow of carbon stars (Image: NASA)
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Scientists will use the new capability to study the formation of interstellar grains in the outflow of carbon stars (Image: NASA)
Custom-built time-of-flight mass spectrometer (TOFS) for COSmIC (Image: NASA/Farid Salama)
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Custom-built time-of-flight mass spectrometer (TOFS) for COSmIC (Image: NASA/Farid Salama)
Bright carbon star, U Camelopardali, surrounded by a cloud of gas and dust (Image: NASA/ESA/HST)
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Bright carbon star, U Camelopardali, surrounded by a cloud of gas and dust (Image: NASA/ESA/HST)
Scanning Electron Microscope image of average nanograins produced in the COSmIC (Image: NASA/Ames/Farid Salama)
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Scanning Electron Microscope image of average nanograins produced in the COSmIC (Image: NASA/Ames/Farid Salama)
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Carl Sagan once said, “We are made of starstuff.” Unfortunately, he was a bit vague about what this starstuff actually is. To help answer that question, scientists at NASA’s Ames Research Center in California have developed a way of recreating the dust and gas found around dying red giant stars that eventually become planet-forming interstellar dust.

Understanding how planets form is one of the key goals of astronomy. The problem is that the only material we have to work with directly is from our own fully-formed planet, or what we are able to gather with our space probes. Until someone invents a faster-than-light drive, the only alternative is for scientists to take what’s known about planet formation and try to reproduce the processes’ raw materials here on Earth.

Many astronomers believe that a key component of the evolution of the universe is the dust produced around dying stars as they use up the last of their hydrogen and helium and the nuclear fusion process starts to break down. Think of it as being a bit like a very old car engine that marks its last trip to the scrap yard by belching soot out the exhaust pipe. In this case, the soot is what eventually forms into cosmic dust clouds, then new star systems, planets, and us.

Scanning Electron Microscope image of a large aggregate of nanograins produced in the Cosmic Simulation Chamber (Image: NASA/Ames/Farid Salama)
Scanning Electron Microscope image of a large aggregate of nanograins produced in the Cosmic Simulation Chamber (Image: NASA/Ames/Farid Salama)

The key component of NASA’s creating synthetic stardust is its Cosmic Simulation Chamber (COSmIC), which was designed and built at Ames. This chamber allows scientists to simulate the gas-phase environment around dying stars. The chamber can create an extremely hard vacuum where pressures are measured in a billionth of an atmosphere, temperatures below minus 270⁰ F (105⁰ K), and ultraviolet and visible light similar to that emitted by nearby stars.

Into this, the scientists spray a cold mixture of argon gas and hydrocarbon molecules, which is then subjected to an electric discharge. As this gas mixture cools further to chamber temperature, the hydrocarbons form particles only a bit over a micrometer in diameter. These are collected for study by a scanning electron microscope and a time-of-flight mass spectrometer that measures mass at a molecular level.

"During COSmIC experiments, we are able to form and detect nanoparticles on the order of 10 nm size, grains ranging from 100-500 nanometers and aggregates of grains up to 1.5 micrometers in diameter, about a tenth the width of a human hair, and observe their structure with SEM, thus sampling a large size distribution of the grains produced," says Ella Sciamma-O'Brien, of the Bay Area Environmental Research (BAER) Institute and a research fellow at Ames.

Bright carbon star, U Camelopardali, surrounded by a cloud of gas and dust (Image: NASA/ESA/HST)
Bright carbon star, U Camelopardali, surrounded by a cloud of gas and dust (Image: NASA/ESA/HST)

Scientist hope that the artificial stardust particles will provide new insights into planet formation as well as helping astronomers to interpret data gathered by Herschel Space Observatory, the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ground-based Atacama Large Millimeter/submillimeter Array observatory in Chile.

"By using COSmIC and building up on the work we recently published in the Astrophysical Journal August 29, 2013, we now can for the first time truly recreate and visualize in the laboratory the formation of carbon grains in the envelope of stars and learn about the formation, structure and size distribution of stellar dust grains," says Cesar Contreras of BAER Institute and a research fellow at Ames. "This type of new research truly pushes the frontiers of science toward new horizons, and illustrates NASA's important contribution to science."

Source: NASA

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4 comments
4 comments
Imran Naqvi
No, Carl Sagan was not vague about what star stuff is. He was very precise. Every atom in our bodies was created during the fusion processes at the heart of stars.
What NASA did was recreate interstellar dust which is another result of those same fusion processes.
Michiel Mitchell
in essence..... it is literally impossible to create fake/artificial stardust... because the raw stuff you used to create it with.... yes you guessed it ... made of actual real stardust....
windykites
I would be interested to hear of a computer simulation of microscopic dust particles existing in free space, and being drawn towards each other by gravity. The gravitational attraction is so infinitesimal, that it seems highly unlikely that particles would clump together at all. Someone tell me I am wrong.
Desann
Windykites1, I think you're right; gravity alone wouldn't be enough to get the ball rolling, so to speak. The theory I've seen is that as the particles bump into each other, it's static electricity that gets them to stick together and form larger bodies. Gravity's effect eventually takes over as the dominant attraction once it gets large enough, and then you've got yourself a planet or star.