From swinging spirals to grand galaxy groups, what creates their swirling spiral arms and what causes galaxies of all shapes to group into clusters? Keith Cooper delves into a world of gravitational resonances while Martin Mobberley acts as your tour guide around the springtime galaxies of the Virgo cluster.

Elsewhere in the magazine, the UK's IYA 2009 coordinator Steve Owens explains how Scotland's Galloway Forest Park became the joint first official dark sky park in Europe, while Paul Abel describes what there is be seen with Saturn at opposition this month. We also take a look at the puzzling case of the variable star epsilon Aurigae as it enters the middle of its latest eclipse phase, to find some of the answers that explain its peculiar behaviour.

We are also pleased to announce the return of our society news pages, Grassroots Astronomy, compiled by Callum Potter. This joins our host of regular sections such as Drawn to the Universe (this month Jeremy Perez tackles digitally sketching double stars), Wonders of the Universe (Carole Stott introduces globular clusters) and Tech Talk (Martin Mobberley investigates big eye pieces). Plus Ian Morison reviews the Intes-Micro MN78 and Steve Ringwood has another bounty of Astroloot, which this month includes a waist case for eyepieces, and a head torch!

All this plus the latest news updates, our 14-page guide to the night sky and astrolistings for events in the coming month.