It really is that deep. Hubble's Ultra Deep Field (revisited in 2012 in this image) takes you back in time, viewing galaxies that formed just 450 million years after the universe began in the Big Bang. That's a short timespan compared to the universe's total age of roughly 13.8 billion years. Aside from a few stars seen with diffraction spikes, every point of light in this image is an entire galaxy – each full of millions or billions of stars. Image credit: NASA, ESA, R. Ellis (Caltech), and the