A light year would be an inappropriate unit of measurement in these circumstances. Earth has a diameter of approximately 12,700km. The distance from Earth to the Moon is approximately 384,400km.

Scientists say they've uncovered the "largest known galactic structure," which spans a mind-boggling 1.4 billion light-years.

Plus, the structure is technically made up of two jets, each about half a light-year across. The black hole in question, which has a mass around 1.4 billion times that of the sun, is located at ...