Dr Kate Hendry has spent 7 months at sea on research ships. So far, she's lived for almost two years in total in the Arctic and Antarctica. In 2017, she was chief scientist on a research expedition to Greenland. In all that time, she's become an expert in collecting animals from the seafloor, gathering tiny plankton, sampling seawater, mud and rocks. She's mapped thousands of kilometres of seabed using sonar. She studies of impact of climate change on past, present and future seas, assesses plastic pollution and advises governments how to protect these fragile, important parts of the planet. In 2022 she is taking up a senior position at the British Antarctic Survey. Dr Helen Scales is a marine biologist and best-selling author.

She's written several articles for National Geographic Magazine about Antarctica, including how climate change is threatening emperor penguins, and (this month) about the urgent need to protect more of the Southern Ocean in marine reserves. Kate and Helen are sisters, who have often been mistaken for one another. Rômolo D'Hipólito is a Brazilian artist and illustrator. He is the winner of the 2019 Golden Pinwheel Special Mention Award and the 2018 Ibero-America Ilustra Catalog Official Selection.