Astronomy Photographer of the Year judges explain how to get involved in astrophotography

In 1884, a delegation of international representatives convened in Washington, D.C. to recommend that Earth’s prime meridian marking zero degrees longitude should pass through the Airy Transit Circle (ATC) at the Royal Observatory in Greenwich, England. But according to the GPS receivers of surveyors and smartphones of London tourists today, why does the line of zero longitude run 102 metres east of the ATC?

A searing solar prominence extends outwards from the surface of the Sun. The ‘wall of plasma’ is the height of three times the Earth’s diameter.

This image is the last winner we have from the eleven categories in the Insight Astronomy Photographer of the Year competition 2015 — that of using a robotic telescope. It shows the power of remote imaging, since Sebastian Voltmer in Germany used the iTelescope at Siding Spring Observatory in Australia to capture Comet C/2013 A1 passing very close to Mars on 19 October 2014.