A massive underground detector aimed at understanding the mysterious ghost particles in our universe released its first major results on Wednesday.

The Jiangmen Underground Neutrino Observatory in China started collecting data in August with the goal of understanding neutrinos: tiny cosmic particles that date back to the Big Bang and whiz harmlessly through our bodies by the trillions every second. Yet they weigh almost nothing, making them difficult to sniff out.

In a study published Wednesday in the journal Nature, the JUNO team unveiled its initial findings from two months of data collection—including some of the most precise measurements to date of how neutrinos switch between three varieties, or flavors, as they zip through space.