The Hubble eXtreme Deep Field, or XDF
Remember how Galileo noticed he could see more stars through a telescope than with his naked eye? Well astronomers are still doing the same thing!
This photo was taken by the Hubble Space Telescope, which is a huge telescope built into a satellite. Because it’s in outer space, there’s no air or dust around, so it’s able to see things billions of times dimmer than what you can see with your eye.
The area of sky shown in the XDF, compared to the moon
This photo is called the Hubble eXtreme Deep Field (or XDF, for short). It is the deepest image we have ever taken of the universe. Only three of the dots in the picture are stars–the rest are galaxies, with billions of stars each. Over 5,000 galaxies are visible in the picture, which shows an area of the sky more than 100 times smaller than the moon!
That’s a lot of stars!
