The galaxy BX442 is so large, so fully-formed, that astronomers say it shouldn't exist at all. It's called a "grand-design" spiral galaxy, and unlike most galaxies of its kind, this one is very old. According to a new study conducted by researchers using NASA's Hubble Telescope, it dates back roughly 10.7-billion years — and that makes it the most ancient spiral galaxy we've ever discovered.
"The fact that this galaxy exists is astounding," said University of Toronto's David Law, lead author of the study. "Current wisdom holds that such ‘grand-design' spiral galaxies simply didn't exist at such an early time in the history of the universe."
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.
Via Dr. Stefan Gruenwald