NASA recently released the largest photo ever taken that shows part of the Andromeda galaxy. The photo is made up of 1.5 billion pixels and the full-sized photo takes up 4.3 GB of disk space. The image shows over 100 million stars and thousands of star clusters in the images that stretches out over 40,000 light-years across one of the edge of the pancake shape discs of Andromeda.
Because the galaxy is only 2.5 million light-years from Earth, it is a much bigger target in the sky than the myriad galaxies Hubble routinely photographs that are billions of light-years away. This means that the Hubble survey is assembled together into a mosaic image using 7,398 exposures taken over 411 individual pointings.
The largest NASA Hubble Space Telescope image ever assembled, this sweeping bird’s-eye view of a portion of the Andromeda galaxy (M31) is the sharpest large composite image ever taken of our galactic next-door neighbor. Though the galaxy is over 2 million light-years away, the Hubble Space Telescope is powerful enough to resolve individual stars in a 61,000-light-year-long stretch of the galaxy’s pancake-shaped disk. It’s like photographing a beach and resolving individual grains of sand. And there are lots of stars in this sweeping view — over 100 million, with some of them in thousands of star clusters seen embedded in the disk.
Check out an amazing zoomable view of the image at SpaceTelescope.org.