Low earth orbit is a vast place, but that doesn’t mean it’s empty.

And as countries across the globe are increasingly using this space for connectivity and research, satellite populations are skyrocketing – and we may witness some close calls.

It was recently revealed that a SpaceX satellite nearly collided with another, unexpected satellite, the source of which is still not fully understood.

According to SpaceX VP of engineering Michael Nicholls, a SpaceX satellite encountered another satellite that had been launched sometime in the previous 48 hours from China’s CAS Space.

Nicholls said “no coordination or deconfliction with existing satellites operating in space was performed” by CAS Space and that the two spacecraft came within 200 meters of one another. As tech reporter Nicholas Werner pointed out, “in space terms, they basically high-fived.”