The universe is really, really big. How big, you wonder? Just think about this. What you see above is an image from the Hubble Space Telescope that shows Abell 1413, a cluster of over 300 galaxies. That cluster is part of Abell catalogue, which consists of more than 4000 rich clusters of galaxies. According to the scientists Abell catalogue is “fairly close to Earth”, although light from there takes 3 billion years to reach our planet. What they mean is that the collection of clusters is close to our planet when we look at it from a cosmological perspective.
Still it’s very difficult to imagine how big the universe is. So we can just stay in our world for now, take a look at Abell 1413 and be amazed. It’s over 2 billion light-years away from us. So Hubble has caught the light that came from there 2 billion years ago. We have no idea what the cluster looks like at this moment. The cluster is seen between the constellations of Leo and Coma Berenices. As you can see, there’s a large galaxy in the picture. It’s an elliptical one called MCG+04-28-097 and it consists of stars that extend up to 6.5 million light-years.
Click here if you want to know more about Abell 1413.