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We are all, literally, made of star dust, says NASA, while announcing that a new study using NASA's Spitzer space telescope observations has revealed for the first time that silica – l & rsquo; One of the most prevalent minerals on Earth – was forming massive stars explode.
Most of the chemicals that make up our planet and our body have been formed directly by the stars.
From glass to sand, silica is literally everywhere: thanks to the explosions of stars
Now look around now and there is a good chance that you will see silica (silicon dioxide, SiO2) in some form, says NASA.
A major component of many types of rock on Earth, silica is used in industrial sand and gravel mixtures for the manufacture of concrete for sidewalks, roads and buildings.
- A form of silica, quartz, is a major component of the sand found on beaches along the US coast.
- Silica is a key ingredient in glass, including plate glass for windows, as well as fiberglass.
- Most of the silicon used in electronic devices comes from silica.
- In total, silica represents about 60% of the Earth's crust.
Its widespread presence on Earth is no surprise, since silica dust has been found in the universe and in meteorites prior to our solar system, as reported by NASA.
Source of dust of star
A known source of cosmic dust is AGB stars, or sun mass stars, which run out of fuel and inflate several times their original size to form a giant red star.
(AGB stars are a type of red giant star.)
But silica is not a major component of AGB star dust, and observations have not determined whether these stars could be the major producer of silica dust observed in the universe.
A supernova is a star much more massive than the Sun which lacks the fuel that burns in its nucleus, which collapses on itself.
The concept of this artist shows Spitzer surrounded by examples of planets examined by the telescope. (Image: NASA)
The rapid drop of matter creates an intense explosion that can fuse atoms to create heavyElements, such as sulfur, calcium and silicon.
Where was the silica detected?
The new study reports the detection of silica in two supernova remnants, called Cassiopeia A and G54.1 + 0.3.
Identify silica in Cassiopeia A
To identify the silica in Cassiopeia A and G54.1 + 0.3, the team used the Spitzer archive data. Infrared spectrograph (IRS) instrument and a technique called spectroscopywhich takes the light and reveals the individual wavelengths that compose it.
(You can observe this effect when sunlight passes through a glass prism and produces a rainbow: the different colors are the wavelengths of light that are usually mixed and invisible to the eye. naked eye.)
The chemical elements and the molecules each emit very specific light wavelengths, which means that they each have a distinct spectral spectrum. digital print'What high-precision spectrographs can identify.
In order to discover the spectral imprint of a given molecule, researchers often rely on models (usually made with computers) that recreate the physical properties of the molecule.
- Running a simulation with these models then reveals the spectral imprint of the molecule
- But physical factors can subtly influence the wavelengths emitted by molecules
- This is the case of Cassiopeia A
Artistic concept of the space observatory Herschel in the space. (Image: Caltech)
Silica grains are shaped football
Although Cassiopeia A spectroscopy data showed wavelengths close to those expected from silica, the researchers were unable to match the data to a particular element or molecule.
Jeonghee Rho, astronomer at the SETI Institute in Mountain View, California, and lead author of the new paper, thought that the shape of the silica grains could be the source of the divergence, since existing silica models assumed that the grains were perfectly spherical.
She began to build models with grains with non-spherical shapes.
Only when she finished a model that assumed that all the grains were not spherical but football shaped that the model "really clearly produced the same spectral characteristic that we see in the Spitzer data, "Rho said.
Identify silica in G54.1 + 0.3
- Rho and his coauthors then found the same characteristic in a second supernova remnant, G54.1 + 0.3.
- Elongated grains can inform scientists about the exact processes that formed silica
How much silica is produced by each star explosion?
The authors also combined the observations of the two supernova remnants of Spitzer with observations from the Herschel Space Observatory of the European Space Agency to measure the amount of silica produced by each explosion.
Herschel detects different wavelengths of infrared light than Spitzer.
The researchers examined the total length of wavelengths provided by both observatories and identified the wavelength at which dust has its maximum brightness.
This image shows the mill's galaxy, also known as the M101, seen by the Herschel Space Observatory of ESA. (Image: Caltech)
This information can be used to measure the dust temperature, and the brightness and temperature are both needed to measure the mass.
We are made of star dust!
This new work implies that the silica produced by supernovas over time was important enough to contribute to dust throughout the universe, including the dust that finally came together to to form our planet of origin.
The study was published on October 24, 2018 in the journal Monthly Notices from the Royal Astronomical Society, and that confirms that every time we look through a window, go down the sidewalk or set foot on a pebble beach, we interact with a material consisting of explosions of stars which burned billions of years.
Herschel and Spitzer's parents
- NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory in Pasadena, California.
- NASA's Herschel Science Center, part of IPAC, supports the American astronomical community
- Caltech manages the JPL for NASA
- JPL Manages Spitzer Space Telescope Mission for NASA's Science Mission Directorate in Washington
- Scientific operations are conducted at Spitzer Science Center in Caltech, Pasadena, California
- The spacecraft operations are based at the Lockheed Martin space in Littleton, Colorado.
- The data is archived in the infrared scientific archive housed at IPAC in Caltech.
Read also | NASA's Spitzer Space Telescope Completes 15 Years in Space: An Overview of Its Achievements
Read also | Did space dust bring life to Earth? We could all all be made of star dust!
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