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

This glorious image of the core of Local Group galaxy Messier 33 (NGC 598) in the constellation Triangulum was captured from Almere, Flevoland, Netherlands by astrophotographer Michael van Doorn — winning image of the Galaxies category in the Insight Astronomy Photographer of the Year competition 2015.

Jamen Percy’s ethereal view of an auroral display over Abisko National Park, Lapland, Sweden was captured with a Canon EOS 5D Mark III camera, 24mm f/1.4 lens and a 4-second, ISO 2000 exposure — winning image of the Aurorae category in the Insight Astronomy Photographer of the Year competition 2015.

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?