A century of galaxy discrimination revealed by giant European astronomy survey

A huge European astronomy survey, whose results are released today (21 December 2017), has revealed that the view of the Universe provided by traditional optical telescopes is seriously biased. The Herschel ATLAS (H-ATLAS) was a survey carried out by an international team led by researchers at Cardiff University with European Herschel Space Observatory in the far-infrared waveband, which consists of electromagnetic waves with wavelengths 200 times greater than optical light. Although Herschel stopped observing in 2013, the Herschel-ATLAS team has spent the last five years analysing their results, and today they released their final images and catalogues, which consist of half-a-million galaxies emitting far-infrared radiation. While the optical light from galaxies is starlight, the far-infrared radiation is from interstellar dust, tiny solid grains of material between the stars. Deeply mysterious. Galaxies, assemblies of stars ranging from 40,000 to thousand billion stars (ours contains about one billion) are the basic building blocks of our Universe. Since they were discovered about a century ago, most of what we know about them has come from optical telescopes.