Brian C. Lacki

In October 2017, the Pan-STARRS telescope in Hawaii spotted an object moving too fast to belong to the solar system. It was 1I/ʻOumuamua, the first interstellar visitor ever recorded by astronomers. Since then, two more have joined it: comet 2I/Borisov and object 3I/ATLAS.

Black holes heavier than a trillion Suns act like cosmic umbrellas. They cast a shadow on the faint afterglow of the Big Bang — ancient light that fills the entire sky. The shadow turns out not blurred, but with a sharp edge, as if cut out with scissors: around it glows a bright ring of photons trapped by gravity.

Civilizations in the Universe are separated not just by distance, but by the vast gulf of time. Hunting for their traces is like archaeology: instead of palace ruins, we find clouds of cosmic dust.

The Moon is a natural archive that has been collecting cosmic dust for billions of years. Among the microscopic grains that arrived from distant stars, there could be techno-specks — particles created by alien civilizations.