Psychedelic Pluto

The early universe was a chaotic mess of gas and matter that only began to coalesce into distinct galaxies hundreds of millions of years after the Big Bang. It would take several billion more years for such galaxies to assemble into massive galaxy clusters — or so scientists had thought. Now astronomers have detected a massive, sprawling, churning galaxy cluster that formed only 3.8 billion years after the Big Bang, some 10 billion light years from Earth.

The first images from the New Horizons spacecraft since late July will come back to Earth on 5 September, and scientists are salivating over what the new pictures will reveal about Pluto.

Planetary nebulae such as Hen 2-437 form when an ageing low-mass star — such as the Sun — reaches the final stages of life. The star swells to become a red giant, before casting off its gaseous outer layers into space. Hen 2-437 is a bipolar nebula — the material ejected by the dying star has streamed out into space to create the two icy blue lobes pictured here.