Category Astronomy/Space

A view of the four central galaxies at the heart of cluster Abell 3827, at a broader range of wavelengths, including Hubble Space Telescope imaging in the ultraviolet (shown as blue), and Atacama Large Millimetre Array imaging at very long (sub-mm) wavelengths (shown as red contour lines). At these wavelengths, the foreground cluster becomes nearly transparent, enabling the background galaxy to be more clearly seen. It is now easier to identify how that background galaxy has been distorted. Credit: NASA/ESA/ESO/Richard Massey (Durham University)

This is a map of the cube of spacetime covered in the new survey, showing the distance to the galaxies in billions of light years. The positions of the 4,000 galaxies appear as circles. The colours represent the degree of redshift seen, with the bluer circles indicating galaxies nearer to the Earth, and so less redshifted. Green, yellow, orange and red circles indicate successively higher redshifts, and galaxies that are progressively further away from the Earth. Credit: D. Sobral

The study significantly narrows the possible temperature of the early Earth to 0 to 50 degrees Celsius. It also finds the ocean’s pH has remained fairly moderate, gradually increasing from a slightly acidic initial value of about 6.6, through the neutral value of 7.0, to today’s slightly alkaline seawater of about 8.1. Credit: Joshua Krissansen-Totton/University of Washington

Artistic composition of the radio telescopes in space and on the ground observing NGC 1275, the central galaxy of the Perseus cluster of galaxies at a distance of 230 million light years. This radio image shows a newly forming jet that is about 3 light years long. The central black hole is inside the bright spot at the top of the image. The details visible in the image are smaller than the Oort’s comet cloud around our solar system. Credit: Pier Raffaele Platania INAF/IRA (compilation); ASC Lebedev Institute (RadioAstron image)