“Well hey, good looking,” is a line I seldom use unless I am chatting up neighboring galaxies. Thanks to NASA’s ultraviolet survey, two of the Milky Way’s galactic neighbors the Large and Small Magellanic Clouds have been photographed and mapped, and though they look stunning, as galaxies are wont to do, they are way out of my league.
When you look up into the night sky with nothing but your jelly-like human eyes, almost everything you see is the contents of the Milky Way galaxy, the galactic landmark us Earthlings call home. Of the hundreds of billions of galaxies in the universe (some report as high as 500 billion galaxies), only a small handful are visible with our puny naked eyes. To study the galaxies of the universe, we have to use sophisticated telescopes that measure all across the spectrum of light to recreate images of existence far beyond Earth. But the Large and Small Magellanic Clouds are relatively close: at only 163,000 and 200,000 light years away, respectively, they are possible to see by the casual observer in the southern hemisphere.
NASA decided to point their Swift satellite telescope at the Large and Small Magellanic Clouds and take a lot of pictures. Nearly 3000 pictures, in fact. And they stitched them together to create a 160-megapixel mosaic image of the Large Magellanic Cloud (LMC) and a 57-megapixel image of the Small Magellanic Cloud (SMC).
“Viewing in the ultraviolet allows astronomers to suppress the light of normal stars like the sun, which are not very bright at such higher energies, and provides a clearer picture of the hottest stars and star-formation regions,” writes Francis Reddy for NASA. The images have incredible sharpness, with an angular resolution of 2.5 arc seconds. This level of precision in space is the equivalent to pinpointing an object the size of a dime from a mile away.
The images NASA put together represent a strange state between what humans, are capable of seeing, and what we aren’t. With the naked eye, we can form a general understanding for the Magellanic Clouds, but with ultraviolet imaging, which isn’t too far from how humans actually see, it becomes apparent that what appears to be a cloud is really a million individual points of light, each representing another star. And while we are accustomed to learning about the vast nature of the universe, the LMC and SMC are relatively small. The LMC is one-tenth the size of our own Milky Way galaxy, and the SMC is half the size of the LMC. On a galactic scale, they embody smallness. But contained within that vignette of cosmos there is massive complexity—a million-point cloud growing from the crucibles of stars.