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?

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

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