If you thought our galaxy was just the luminous matter within it, think again.
“Things need not have happened to be true. Tales and adventures are the shadow truths that will endure when mere facts are dust and ashes and forgotten.” –Neil Gaiman
It’s easy to look at the night sky and find that it’s full of stars.
Moreover, the stars cluster together in a great plane spanning the sky, making up our galaxy: the Milky Way.
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.
If you’re trying to measure distant nebulae, galaxies, supernovae or the effects of dark energy, it will throw off your results.
Nearly complete sky maps from 2MASS and PAN-STARRS surveys come to the rescue.
With that multiwavelength data, Edward Schlafly and collaborators constructed the first 3D dust map of the Milky Way.
Future studies, especially of dark energy, will be much more accurate as a result.
Surprisingly, the size of dust grains hardly changes at all with where we look.
So why does dust clump together more densely in some places?
That’s a mystery requiring additional studies to solve.
Mostly Mute Monday tells an astronomical story in pictures, visuals and no more than 200 words total.
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