More Than Stars: The Milky Way’s Dust Mapped In 3D For The First Time Ever
“But the Milky Way is more than just stars, it’s also full of gas, plasma, and – most importantly – light-blocking dust. This dust indicates where clumped neutral atoms are, reddening the stars behind it, but not in front of it. Where the dust is coolest and densest, future stars will someday form. Preferentially blocking bluer light, this dust distorts our view of any background objects.”
Wherever we look in the night sky, we don’t just observe the background sources of light shining our way, but also the effects of all the matter in between those distant sources and our eyes. Since all of that inbound light needs to pass through a portion of the Milky Way on its way to our eyes, it’s vital that we understand how that light is distorted by our own galaxy. That means we need an understanding of the dust in our own neighborhood. In the past, that meant using a variety of models, but for the first time, a 3D map of the Milky Way’s dust has been constructed. This will not only allow for a better calibration of distant objects – such as galaxies, supernovae and anything we’d use to measure dark energy – but it uncovers some surprises about the fundamental nature of dust itself.