An urban collection of modern-day micrometeorites

More than 100 billion micrometeorites (MMs) fall to Earth each year. Until now, scientists believed that these particles could only be found in the cleanest environments, such as the Antarctic. In their new paper for Geology, M.J. Genge and colleagues show that, contrary to that expectation, micrometeorites can be recovered from city rooftops (for this example, primarily in Norway) and that, unlike those from the Antarctic, they are the youngest collected to date.