What is cosmic dust? In simple words, cosmic dust is a collection of extremely tiny solid matter particles which drifts around in space, like a few molecules across. On average, around 4,700 metric tons of dust falls onto the Earth every year from the universe.
When Sun-like stars collapse and explode as a supernova, the combined garble of elements(like helium, carbon, oxygen, iron and many more) contained within their dense cores are expelled into the universe. The elements form molecular clouds with heavier elements like iron and silicon forming minerals after combining with oxygen. Those molecular-sized mineral grains are actually cosmic dust. These play a crucial role in planet and stars formation. After being expelled from a star, dust can drift to another part of the universe creating another star, and so on. Cosmic dust particles are similar in size to shorter wavelengths of light, having the ability to absorb or scatter those wavelengths. On the other hand, we know that longer wavelengths of light, like red light, pass directly through dust clouds(Interstellar Reddening). The dust clouds absorb or scatter all the light, making stars tucked behind them look more red and faint. For a regular telescope, most of the light reaching the telescope will fall outside the visible light spectrum, making them invisible. ‘
Thanks to Willian Herschel, whose discovery of infrared light in 1800, opening a bunch of possibilities. Longer infrared wavelengths are being utilized to see beyond the naked eye and through the dust. Now comes the James Webb Space Telescope. James Webb Space Telescope can even observe much longer infrared wavelengths.
Amazingly, this observatory can analyze a much wider range of light when paired with its advanced detectors. Apart, from this, the Webb telescope is even expected to solve the “dust budget crisis”, which is the inability to account for all the dust found throughout the universe. Webb will be working with JAXA to observe infrared light from Wolf-Rayet stars (supermassive stars at a very late stage of stellar life). They’ve been seen releasing dust in a pinwheel pattern when observed in infrared light (like WR 112, which astronomers describe as a “highly efficient dust factory”). Webb will be able to observe the chemical signatures produced from Wolf-Rayet stars after reaching to the skies, enabling us to figure out how the universe got so dusty.