In June 2012 one of the solar system’s rarest of astronomical events took place, when it was possible to see the planet Venus fly past the face of the Sun. It appears when the orbits of Earth and Venus momentarily line up, but that happens only four times every 243 years. Astronomers in Australia, London and Hawaii tell Nick Holland what it was like watching the sight, one they will never get to see again because they won’t be alive when it next reappears in the year 2117.

(Image: SDO satellite captures an ultra-high definition image of the transit of Venus. Credit Nasa/Getty Images)