SAN ANTONIO -- "You see the sun with Venus," exclaimed 14-year-old Sarah Chevalier.
Even as a teenager she understands the impact of today's event. "The next time, 115 years," she said.
That's because the event, which gives curious spectators the opportunity to witness Venus cross the path of the sun, last occurred in 2004. However, it won't happen again for another 115 years.
Members of SALSA -- San Antonio League of Sidewalk Astronomers -- gathered at McAllister Park on Tuesday evening to witness the rare planetary spectacle.
Not everyone stayed home for the vision. KENS 5 has learned a local private school actually traveled to Hawaii to see the transit. That's apparently the best place to see it, and from where NASA broadcast the transit.
Back in the 18th century, astronomers believed that studying the transit of Venus would provide the answer to one of the most pressing questions of the time: How big is the solar system?
Based on measuring the timing and angles of Venus crossing, the distance between the Earth and the sun could be calculated.
An interesting anecdote from the 18th century involves astronomer David Rittenhouse's 1769 viewing of the Venus transit. When Venus finally appeared, Rittenhouse fainted, causing him to miss the beginning moments of a historical moment of discovery.
Today, we know the distance from the Earth to the sun is approximately 93 million miles -- not far off from the measurements of the 18th century astronomers.