How long would it take to count all of the stars in the sky? Well, if the latest imagery by NASA is anything to go by it would be a bit longer than we all probably estimated.
NASA have released their largest ever image, a 1.5 billion pixel composite photo of our closest galaxy Andromeda. The image by the Hubble Space Telescope stitches together 7,398 different exposures and captures over 100 million stars which occupy a 61,000 light-year-long stretch of space.
And this is only a portion of the pancake-shaped disk galaxy. "It's like photographing a beach and resolving individual grains of sand." says NASA. It's the first time that astronomers are able to look at individual stars inside another spiral galaxy over such a huge area.
Hubble traces densely packed stars extending from the innermost hub of the galaxy seen at the left. Moving out from this central galactic bulge, the panorama sweeps from the galaxy's central bulge across lanes of stars and dust to the sparser outer disk. Large groups of young blue stars indicate the locations of star clusters and star-forming regions. The stars bunch up in the blue ring-like feature toward the right side of the image. The dark silhouettes trace out complex dust structures. Underlying the entire galaxy is a smooth distribution of cooler red stars that trace Andromeda’s evolution over billions of years.
Here's what a small area looks like zoomed all the way in. You can check out the full zoomable image here. To view the actual 1.5 gigapixel image you'd need more than 600 HD television screens.
And in the video above YouTube user daveachuk gives the mind-blowing image some context.