Some skeletons are more sparkly than scary. A new image of a far-off galaxy shows us that what lurks underneath a spiral galaxy can be just as spectacular as what our eyes can see. The new images taken by the James Webb Space Telescope’s Mid-InfraRed Instrument (MIRI) show IC 5332, a spiral galaxy about 29,000 light years away from the Earth in the constellation Sculptor. It has a diameter of roughly 66,000 light years, making it slightly larger than our Milky Way galaxy.
The MIRI aboard the new telescope observes the furthest reaches of the universe and can see infrared light, so it’s able to peer through the galaxy’s clouds of dust and into the “skeleton” of stars and gas underneath its signature arms. MIRI basically was able to take an x-ray of a galaxy, revealing IC 5332’s bones and a world that looks different, yet somewhat the same.
The dust between the arms of the galaxy virtually disappear in this new image, and it also shows some blood-red stars that were missed or blocked in previous pictures taken by the three-decade old, but still kicking, Hubble Space Telescope. Comparing and contrasting these the two images will help astronomers learn more about how stars, dust, and gas interact within swirly spiral galaxies and the specific properties of IC 5332.
According to the European Space Agency (ESA), obtaining observations in the mid-infrared range like the scale that the JWST can see, is incredibly challenging from Earth, partially because Earth’s atmosphere absorbs most of the light. The heat from the atmosphere also complicates things. The Hubble can’t observe the mid-infrared region because as its mirrors weren’t cold enough, meaning the “infrared radiation from the mirrors themselves would have dominated any attempted observations,” writes the ESA.
MIRI operates 91 degrees Fahrenheit (33 degrees Celsius) colder than the rest of the observatory aboard the JWST which rests at a chilly 466 degrees Fahrenheit (-266 degrees Celsius). That means that MIRI operates in an environment only 44 degrees Fahrenheit (7 degrees Celsius) warmer then absolute zero, or the lowest possible temperature based on the laws of thermodynamics. This super cold environment is needed for MIRI’s highly specialized detectors to function correctly.
IC 5332 shows up as a pristine image of a spiral galaxy in the wavelengths of light that are visible to the human eye, but this new image shows just how much goes into those dreamy swirls. This galaxy is also notable because it is almost perfectly face-on with respect to Earth, which allows us to better see the symmetrical sweep of its spiral arms from our corner of the universe.