Most of the chemicals that in our planet and our bodies were formed directly by stars. Now, a new study using observations by NASA‘s Spitzer Space Telescope reports for the first time that silica is formed when massive stars explode.
Silica is the most common minerals found on Earth. Present in many types of rocks on Earth, it is used in industrial sand-and-gravel mixtures to make concrete for sidewalks, roads, and buildings. Silica is also a key ingredient in glass.
Undoubtedly, 60% of Earth’s crust is made from silica. Apart from that, silica dust is also found throughout the universe and in meteorites that predate our solar system. One known source of cosmic dust is AGB stars or stars with about the mass of the Sun that is running out of fuel and puffs up to many times their original size to form a red giant star.
The new investigation reports the identification of silica in two supernova remainders, considered Cassiopeia A and G54.1+0.3. The fast in-fall of matter makes an extreme blast that can fuse atoms to make heavy components, similar to sulfur, calcium and silicon.
For this study, scientists used archival data from Spitzer’s IRS instrument and a technique called spectroscopy, which takes light and reveals the individual wavelengths that compose it.
The spectroscopy data of Cassiopeia A showed wavelengths close to what would be expected from silica, researchers could not match the data with any particular element or molecule.
Jeonghee Rho, an astronomer at the SETI Institute in Mountain View, California, and the lead author on the new paper, thought that perhaps the shape of the silica grains could be the source of the discrepancy, because existing silica models assumed the grains were perfectly spherical.
She began building models that included some grains with nonspherical shapes. It was only when she completed a model that assumed all the grains were not spherical but, rather, football-shaped that the model “really clearly produced the same spectral feature we see in the Spitzer data,” Rho said.
Rho and her coauthors on the paper then found the same feature in a second supernova remnant, G54.1+0.3. The elongated grains may tell scientists something about the exact processes that formed the silica.
The creators additionally combined the observations of the two supernova remainders from Spitzer with perceptions from the European Space Agency’s Herschel Space Observatory with the end goal to gauge the measure of silica delivered by every blast. Herschel distinguishes diverse wavelengths of infrared light than Spitzer.
The specialists took a gander at the whole range of wavelengths given by the two observatories and recognized the wavelength at which the residue has its pinnacle splendor. That data can be utilized to quantify the temperature of residue, and both brilliance and temperature are vital with the end goal to gauge the mass. The new work suggests that the silica delivered by supernovas after some time was sufficiently huge to add to tidy all through the universe, including the residue that at last met up to shape our home planet.
The study was published on Oct. 24, 2018, in the Monthly Notices of the Royal Astronomical Society, and it confirms that every time we gaze through a window, walk down the sidewalk or set foot on a pebbly beach, we are interacting with a material made by exploding stars that burned billions of years ago.