A transit is an astronomical term for when one object passes another. In the photograph below the planet Mercury is transiting across the Sun, as seen from the SOHO spacecraft.

For the first time scientists have recorded the Moon’s transit of Earth. The footage was taken by NASA’s Deep Impact spacecraft, the same spacecraft that fired a block of copper into a comet (9P/Tempel) to analyse the ejecta produced and thereby study the comet’s interior.