This edition of Images of the month showcases strange snails, space debris in the Amazon River and newly digitized photographs from the American Museum of Natural History.

Shell games

Thor-Seng Liew and Menno Schilthuizen, at Leiden University in the Netherlands, have been investigating how the incredible shapes of mollusc shells protect their occupants against predators, and how this forces predators to modify their strategies. Despite these adaptations, the Plectostoma snails that once lived in the shells pictured still became another animal’s dinner, the researchers report in PeerJ (Liew, T.-S. and Schilthuizen, M. PeerJ 2, e329; 2014). Credit: Thor-Seng Liew

Digitizing natural history

Stairways to Heaven

The mobile gantry shown here helps staff at the European Space Agency to prepare rockets for launch from French Guiana. This photo was taken by Edgar Martins and is included in his book The Rehearsal of Space and The Poetic Impossibility to Manage the Infinite. But what goes up… Credit: Edgar Martins/ESA

Fisherman’s big catch

...must come down. A fisherman on the Amazon River in northeast Brazil unearthed a novel, and fortunately very rare, piece of pollution in April — a piece of a space rocket, emblazoned with a UK space agency logo. Credit: Tarso Sarraf/Reuters/Corbis

Messier complex

This complexity of light sources is a 13-billion-year-old cluster of stars some 7,665 parsecs (25,000 light years) away called Messier 5. This image from the Hubble Space Telescope was released 21 April. Credit: ESA/Hubble and NASA

Canada on the rocks

Every year NASA’s Operation IceBridge sets out to fly over and image Earth's polar ice. This image was captured above Canada’s Ellesmere Island as ground- and air-based teams measured the snow depth at the end of March. Credit: Michael Studinger/NASA

And finally …