With radio and infrared telescopes, astronomers can pierce the dusty veil of our galaxy and map its farthest reaches
This infrared image from NASA's Spitzer Space Telescope shows the nebula nicknamed "the Dragonfish." This turbulent region lies beyond the galactic center—effectively on the dust-obscured "far side" of our galaxy—and is home to some of the most luminous massive stars in the Milky Way. You'd think, given that we live inside the Milky Way, we would have a pretty good map of it by now, together with an understanding of its overall structure and components. Being embedded in the Milky Way is actually a major obstacle to our galactic cartography, however. We see every other galaxy from the outside, allowing us to observe most of them sprawled out before us. That makes mapping their structure relatively easy. But for our own Milky Way, we're stuck inside with a murky view. Imagine you're in a giant, fog-filled warehouse where you can always see the floor and ceiling, but the gloom blocks any deep view to the building's perimeter. You can see the boxes and other goods stacked up on nearby shelving, yet your spatial awareness fades past a dozen meters or so. You can't tell what's out there; you don't even know how far away the walls are or if you're near the warehouse's periphery or its center. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Astronomers face this very issue. If our galaxy were just made up of stars, we'd be able to see clear across it. But it's also filled with dust: tiny grains of rocky or sooty material created when massive stars die, blown out in a vast wind that expels the grains into space. Billions of these stars over billions of years have choked the Milky Way with dust, filling it with opaque clouds, blocking our sight line and limiting our view. Essentially all the stars we can see are on our "near" side of the Milky…