Researchers from Imperial College London have discovered fossilized micrometeorites in sedimentary rocks in the Dover Cliffs that formed during the Cretaceous. The scientists plan to analyze these samples and learn about the early solar system.
The discovery was reported in Earth and Planetary Science Letters, with the team stressing how common these micrometeorites are expected to be in the geological record. The particular deposit that was analyzed in this study is 87 million years old – older than the T-rex.
“The iconic white cliffs of Dover are an important source of fossilized creatures that help us to determine the changes and upheavals the planet has undergone many millions of years ago,” lead author Martin Suttle said in a statement. “It is so exciting because we’ve now discovered that fossilized space dust is entombed alongside these creatures, which can also provide us with information about what was happening in our solar system at the time.”
An important breakthrough in this research was estimating how much the cosmic dust changes as it fossilizes. The geological processes that change sedimentary rocks also affect the micrometeorites in the rock. This makes the identification of cosmic dust in rocks difficult. Luckily, the distinctive spherical and Christmas tree-like form of cosmic dust was a clear giveaway in these rocks.
In parallel to this discovery, the team has published a second piece of work on how to determine the clay content in fossilized cosmic dust. Clay forms in the presence of water, and studying the cosmic dust might tell us about the water distributions in the solar system.
“In the distant future, asteroids could provide human space explorers with valuable stop offs during long voyages. Being able to source water is vital because it can be used to drink, to make oxygen and even fuel to power spacecraft,” Dr Matt Genge, lead author of the second study, stated. “The relevance of our study is that cosmic dust particles that land on Earth could ultimately be used to trace where these water-rich asteroids may be, providing a valuable tool for mapping this resource.”