|Credit: NASA, ESA and P. Oesch (Yale University)|
Unfortunately, some of those reporting this went a step too far with headlines like this:
Here's a few more iffy remarks:
- 'GN-z11 is a record-breaking 13.4 billion light years away...'
- 'Located a record 13.4 billion light years from Earth...'
- 'NASA's Hubble Space Telescope has discovered the most remote galaxy ever seen from Earth - 13.4 billion light years away.'
- 'A galaxy 13.4 billion light years away has been spotted by the Hubble Space Telecope.'
How far away? We don't know for certain. The calculation is messy. Luckily Edward Wright of UCLA has produced a calculator that will give us a feel for just how far away the galaxy is. The bad news is that there are several factors that have to be entered into the calculator, including an assumption about the nature of the curvature of the universe, Hubble's constant, which relates the redshift to the distance, and the proportion of matter and dark energy - the more dark energy, the faster the acceleration of the expansion. (I slightly over-simplify the model, but that's a fair picture.)
Plugging in what seem to be the best accepted current values into the calculator comes up with an approximate 'comoving radial distance', the most meaningful measure to call the distance to the galaxy, of around 31.8 billion light years - rather more than 13.4. Far, far away indeed.