For the last time in our lifetime, Venus has passed between the Earth and the sun.
The planet appeared as a small black dot in the sky while literally passing between us and the sun between 5 p.m. and 11 p.m. Tuesday. The rare event, called the Transit of Venus, won't happen again for another 105 years, until 2117.
Astronomers and those with even a passing interest in the stars flocked to Chicago's Adler Planetarium, where specially outfitted solar telescopes were provided for safe viewing.
With any solar event, people should never look directly at the sun.
The Adler offered free general admission for Illinois residents who provided proof of residency in observance of their discount day.