Every year around 4,700 metric tons of interplanetary dust particles hit our planet’s surface, as per a new study. The study suggests that cosmic dust is the prime source of extraterrestrial material on Earth, rather than meteorites. Space rocks only contribute less than 10 tons of material every year.
This information might help astronomers understand the role of extraterrestrial material in supplying water and carbon molecules in the early days of our planet. However, extracting these dust particles is a very tough task. It is due to their tiny size; these micrometeorites measure just a hundredth of a millimeter in size. For this, scientists need a blank canvas that doesn’t have terrestrial dust and what better place than Antarctica?
In the last 20 years, physicist Jean Duprat of the CNRS has led several research operations to the Franco-Italian Concordia station (Dome C) in Antarctica. Thanks to the low snowfall rate and good snow conditions, it’s the best place to look for cosmic dust.
The team collected pure snow samples from 2 meter deep trenches to avoid human contamination of the samples. In 20 years researchers have extracted enough micrometeorites of 30 to 300 micrometers in size to calculate the amount of extraterrestrial dust that falls on Earth every year.
It was estimated that a total of 13,600 metric tons of cosmic dust falls on the Earth’s surface each year; however, most of it turns to ash as it enters the atmosphere. The study also shows that around 80% of the cosmic dust is from Jupiter’s family comets. These comets mostly are formed in the Kuiper Belt, just beyond Neptune’s orbit. The rest 20% of the extraterrestrial dust is said to come from asteroids.
These findings are a result of the collaboration between astronomers from the CNRS, the Paris-Saclay University, and the National museum of natural history. The French polar institute has also extended its support for the study. The paper can be found in the journal Earth & Planetary Science Letters.
