Peer up into the sky on a clear night away from city lights, and you’ll be able to see about 4,500 stars. That’s nothing compared to the number of stars in our galaxy alone, which is between 100 and 400 billion. The incredible technology we have has allowed us to see even beyond that into galaxies beyond our own. This begs the question: what’s the farthest object we’ve ever spotted?
1. Meet Icarus, the farthest star we’ve ever seen.
Icarus is a blue star of enormous size that’s a whopping 9 billion light years away. It was discovered by Hubble in 2016 purely by accident. Hubble’s task was to look at a supernova when it caught sight of a little point of light. That light was Icarus, a blue supergiant.
2. Made possible by gravitational lensing.
Under ordinary circumstances, there’s no way we would be able to see an individual star that’s so far away. But the universe does something called gravitational lensing, which is when the gravity from a large galaxy cluster magnifies the light from stars behind it. Through gravitational lensing, Icarus appears about 2,000 times brighter than it actually is.
3. Will we be able to see farther?
Hubble is an incredible telescope, but it’s also getting old. It has far exceeded expectations, yet still it’s time for us to bring in something new. The James Webb Telescope is set to launch in 2021 and will look at the universe in the infrared spectrum. This will allow it to see things that were missed or overlooked in the past, and it will have a deeper range than Hubble. Can you imagine the discoveries on the horizon?