This astonishing picture was taken just 30 hours before the transit began, when the Sun and Venus were separated by only 2.3 degrees (for comparison, the Sun itself is 1/2 a degree across). The ring around Venus is due to sunlight scattered through the thick atmosphere of the planet. The picture was taken using the 0.73-meter National Solar Observatory/Dunn Solar Telescope.

Credit: NSO/DST - IBIS; INAF / Osservatorio Astrofisico di Arcetri