“People hear the happy story, but the truth is they could all disappear in the blink of an eye. The threats just keep coming.” -Todd Steiner
It’s taken generations of scientists, examining the night sky for millennia, to comprehend the full size and scope of what’s out there in the Universe.
Image of the southern Milky Way, by A. Fujii.
Out beyond the planets and stars, outside of the Milky Way itself, is a great cosmic abyss filled with still-uncounted galaxies that stretch for billions of light years across the Universe.
Image credit: 2P2 Team, WFI, MPG/ESO 2.2-m Telescope, La Silla, ESO.
More precisely, there are over 100 billion galaxies in our observable Universe, which is the Universe within about 46.5 billion light years of our present location. The deepest observation we’ve ever made — the Hubble eXtreme Deep Field (XDF) — has recently upped the number of galaxies to closer to 200 billion as a lower limit, with possibly many more than that still lurking undiscovered.
Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team.
But you might know that the Big Bang, or ...