Dust. It's the bane of homeowners and astronomers alike, a persistent nuisance that collects in corners and on shelves - and which can also get in the way and make peering across the galaxy and out into the universe more difficult than it already is.
Dust is especially worrisome for scientists at the Berkeley Lab who are developing a project called the Dark Energy Spectroscopic Instrument (DESI). The ultimate goal of this instrument, slated to begin operating by 2019, is to precisely measure how quickly the universe is expanding. To do so, DESI will build a map of more than 30 million distant galaxies.
But that map will be inaccurate if astronomers don't account for distortions caused by the dust that pervades our galaxy, the Milky Way. Just like astronomers need to correct for distortions caused by the effects of our atmosphere, they also need to correct for the effect of the dust grains that block and affect astronomical observations.
"The light from those distant galaxies travels for billions of years before we see it," said Edward Schlafly from the Berkeley Lab, "but in the last thousand years of its journey toward us a few percent of that light is absorbed and scattered by dust in our own galaxy. We need to correct for that."
Schlafly and his team figured out the best way to deal with the dust was to build a 3D map of it - and this turned out to be a lot cooler than it sounds, because once they created the 3D map, they then created a detailed fly-through video of the dust in our galaxy.