That grainy image above is one of the oldest and most distant things we’ve ever seen as a species.
On Tuesday, the European South Observatory published this image of a distant celestial object called H-ATLAS J142935.3-002836 — the collision of two disc-shaped galaxies that occurred about seven billion years ago, when the universe was only half as old as it is now. The image is the result of several different views, produced by both ground-based and space telescopes at a number of different wavelengths.
Because light takes time to travel, when we look extremely far away, we’re actually seeing events that occurred some time ago. And this object is so far that the light it produced took roughly seven billion years to get here.
We’re only able to see it at all because of a neat trick called gravitational lensing. Basically, when a much closer galaxy is aligned directly in between us and the distant one, the light coming from the far galaxy is actually bent by the gravity of near galaxy as it comes towards us. This makes the far galaxy much brighter — in this case, bright enough for us to see it.
To get a better idea of just how far away this thing is — and how gravitational lensing works — watch the ESO video below.