60 Tons of Cosmic Dust Fall to Earth's Surface Each Day
Every day, thousands of pounds of cosmic dust falls into Earth's atmosphere from space and eventually lands on the surface. Exactly how much has been highly uncertain, with previous estimates varying widely from .4 to 110 tons. Now, a new study makes a far more precise estimate, at a whopping 60 tons of cosmic dust per day.
Every day, pieces of meteors, comets, and other celestial objects in our solar system fall into our atmosphere as we travel through comet trails and destroyed asteroid belts, the remnants of the chaotic accretion process in our solar system formation. A small number are large enough to be visible as shooting stars, while the rest are burned away in our upper atmosphere. When these pieces are consumed, they dissolve into a cloud of cosmic dust, known as "meteoric smoke," which ultimately falls onto Earth's surface.
Previous estimates of the amount of cosmic dust that lands on our planet have been based on relatively inexact measurements, such as the concentration of cosmic elements in polar ice caps, but the range was too wide to be meaningful. For this study, the researchers narrowed that range considerably by comparing the amount of sodium and iron particles in the atmosphere with models of how cosmic dust is transported. Sodium and iron particles are thought to be the remnants of cosmic dust, so it stands to reason that their concentrations would be proportional to the amount of cosmic dust. This process yielded the approximation of 60 tons of cosmic dust per day.
This information is interesting on its own, especially if you consider what that amount of cosmic dust would look like if it were accumulated in one place. But the dust has other, more practical uses as well, such as assisting cloud formation and helping to fertilize plankton in Antarctica. The researchers hope that an increased understanding of the phenomenon of cosmic dust on Earth will help them understand the substance's wider applications.