The hallmark of a grand design galaxy is its well-formed spiral arms, but getting into this conformation takes time. When astronomers look at most galaxies as they appeared billions and billions of years ago, they look clumpy and irregular. A 10.7-billion-year-old entity, BX442 came into existence a mere 3-billion years after the Big Bang. That’s not a lot of time on a cosmic time scale, and yet BX442 looks surprisingly put together. So much so, in fact, that astronomers didn’t believe it at first, chalking their unusual observation up to the accidental alignment of two separate galaxies. But further investigations, conducted at the W.M. Keck Observatory in Hawaii, revealed BX442 to be the real thing.
So how does a galaxy that shouldn’t exist come to be? The researchers think the answer may have something to do with a companion dwarf galaxy looming near BX442 (in the image up top, it’s the separate circular cluster in the upper right). Simulations conducted by University of Arizona researcher Charlotte Christenson indicate that gravitation interactions between the two, which she says appear to be in the process of colliding, may have helped BX442 take shape.