Over the decades, a variety of space agencies have taken spectacular images of distant galaxies. In these images, we see beautiful spiral arms that are thousands of light-years long, huge bulging disks of dust and gas surrounding supermassive black holes, the brilliant glow of enormous starburst regions, and a number of other glorious sights.
And although the Milky Way is a wonderful and spectacular place—a place filled with beautiful celestial objects—we will never get to see our home galaxy in the same light.
The Milky Way is over 100,000 light-years across. That is 587 quadrillion miles, or 946 quadrillion kilometers. In other words, it’s really big. Since it is so big, it would take us generations to get a spacecraft far enough away from the Earth to take a picture of our galaxy. Sadly, no one alive today will ever see such an image.
But this NASA image may very well be the next best thing. In this spectacular image, NASA used infrared light and X-ray light to see through the obscuring dust in our galaxy and reveal the intense activity near the galactic core. This activity occurs against a fiery backdrop in the crowded, hostile environment of the galaxy's core, the center of which is dominated by a supermassive black hole nearly four million times more massive than our Sun (the center of the galaxy is the bright white region that you see slightly to the right in the image).
Permeating this region of the galaxy is a blue haze of X-ray light from gas that has been heated to millions of degrees by outflows from the supermassive black hole as well as by winds from massive stars and by stellar explosions. Infrared light reveals more than a hundred thousand stars, along with glowing dust clouds that create complex structures throughout the galaxy.