The Hubble Ultra Deep Field is the deepest visible-light image of the Universe ever taken. Containing almost 10,000 galaxies caught everywhere from having just formed 800 million years after the Big Bang (the smallest and most red-shifted) to mature galaxies whose light left them only a billion years ago (larger elliptical and spiral galaxies). This image was composited from 800 exposures taken over 400 orbits. Viewed from Earth, the portion of the sky in this photo appears almost empty of visible stars, and is just one-tenth the diameter of the Full Moon—it’s like “looking [at the sky] through a 2.5 metre-long soda straw.”