A galactic bulls-eye ringed with pink nebulae is the only evidence of a rare galactic collision of NGC 922 that occurred millions of years ago.
Explore this awesome image from the NASA/ESA Hubble Space Telescope. What shapes or stories do you see? Leave a note in the comments below.
NGC 922 used to be a spiral galaxy. But as you zoom across the image, the spiral arms look distorted and disrupted. Tell-tale signs of a galactic interaction are many from the large numbers of bright pink nebulae and blue stars to the spray of dim stars toward the top of the image. Ripples set up as the smaller galaxy passed through the gas and dust clouds of NGC 922 created new star formation. Ultraviolet radiation from these bright new stars cause hydrogen gas in the surrounding nebula to glow a characteristic pink. The tugs of gravity hurled thousands of stars outward.
Scientists believe that millions of years ago a small galaxy, known as 2MASXI J0224301-244443, plunged through the heart of NGC 922. Sometimes, if a small galaxy hits a larger galaxy just right, a circle is formed. But more often than not, galaxies are not aligned perfectly. When a galaxy smacks another off center, one side of the ring is brighter than the other. NGC 922 is a prime example of what astronomers call collisional ring galaxies.
As you explore the empty places of the image, look for faraway background galaxies. Several dim spiral galaxies dot the image both outside the galaxy and within the star-speckled interior.
NGC 922 is found about 330 million light-years from Earth toward the constellation Fornax. Fornax, the Furnace, is a constellation we haven’t visited before. Introduced by sky mapper and French astronomer Nicolas Louis de Lacaille in 1756, Fornax is relatively devoid of stars allowing astronomers to peer deep into the universe. Astronomers targeted Fornax for the Hubble Ultra Deep Field image.