Watching Venus Transits Across the Centuries

A Venus transit occurs when Venus passes directly between Earth and the Sun.
The planet appears as a small black dot moving across the Sun’s disk.
These events are among the rarest in astronomy, happening in pairs eight years apart, over a century apart.
The last pair occurred in 2004 and 2012; the next won’t happen until 2117 and 2125.
In the 18th century, global expeditions observed transits to calculate the astronomical unit (Earth–Sun distance).
The 1761 and 1769 transits were watched worldwide, inspiring international collaboration.
Famous explorers like Captain Cook traveled to remote sites to observe them.
Venus transits helped prove that planets follow precise, predictable orbits.
Modern transits were observed with spacecraft and advanced telescopes for maximum precision.
Watching Venus cross the Sun has linked centuries of astronomers in a shared quest to measure the cosmos.