• Too chilled out: we meant to refer to “frozen carbon monoxide” on the surface of Pluto (17 October, p 6).
• Some figures we gave for global production of lithium were for the gross weight of compounds in which lithium is contained: the true weight of lithium extracted in 2013 was 31,300 tonnes (17 October, p 38). And Antofagasta is 350 kilometres to the west of the Salar de Atacama.
