Proba-2 watches Mercury transit

ESA's Proba-2 had a ring-side seat for the transit of Mercury on 11 November 2019.

Proba-2 monitors the Sun from Earth orbit and was able to spot Mercury’s transit as a small black disc – seen here to the right of centre as it passed across the face of the Sun. The image was taken with the SWAP extreme ultraviolet telescope.

Solar transits – where a celestial body is seen to pass across the solar disc from the perspective of Earth – are relatively rare events. Mercury undergoes around 13 transits a century, and will not occur again until 2032.