When we observe distant celestial objects, there is a possible catch: Is that star I am observing really as reddish as it appears? Or does the star merely look reddish, since its light has had to travel through a cloud of cosmic dust to reach our telescope?

Previous efforts to map the galaxy's dust were challenged by limited data, but the Gaia mission has provided a treasure trove of information.

Voluminous clouds of cosmic dust permeate our galaxy, but only recently has software allowed detailed observations of the stuff at scale.