• As several readers have pointed out, the correct answer to the puzzle “which box has been opened up?” on the cover of 12 January issue is “none of them”: a symbol was rotated through 30 degrees.
• The article “The D’oh! of tech” (22/29 December 2007, p 54) claimed that the BLAST telescope weighed 180 kilograms when in fact it weighs 1800 kg; and Autosub 2’s missions in 2003 were to take physical oceanography measurements, not to survey biodiversity. They were its first under a permanent ice shelf, following trips under seasonal sea ice in 2001 and 2002.
