It's early morning on June 8; 6.19 and 46 seconds to be precise. And it is so important to be precise today, writes Steve Farrar.
A select audience of scientists and historians at the University of Central Lancashire's observatory trains solar telescopes at the sunrise in confident anticipation.
As the silhouette of the planet Venus takes a dainty nibble from the brilliant disc of the sun for the first time in 120 years, they voice their appreciation. "Breathtaking", "absolutely gorgeous", "holy smoke!".
It is a profound, beautifully minimalist performance as a small, perfectly circular dot glides for six hours across the sun.
The academics return again and again to take another look. One astronomer confesses he has not looked through a telescope for more than a decade.
Today he feels compelled.
Allan Chapman, the distinguished Oxford University historian of science who greets the transit in his dinner jacket, ponders how fortunate Jeremiah Horrocks and William Crabtree were with the weather during their seminal observations of 1639. Leaden Lancashire skies came close to robbing them of their half hour of glory.
The academics are not here to celebrate luck. They are marking a great triumph of insight, calculation and prediction over nature.
In itself, a glimpse of the solar system's clockwork has little left to tell today's scientists.
But there is something powerful in being able to predict events over 93 million miles of space to the very second.
John Ponsonby, a former scientist at Manchester University's Jodrell Bank, beams: "It's beautiful confirmation that we understand how the solar system works to a very high degree."
It is also a moment for the mix of historians and scientists attending the transit conference to reflect on past pioneers.
Wayne Orchiston, research associate at the Anglo-Australian Observatory, remarks: "I keep looking through the eyepiece and thinking about the human drama."
Nearby in Much Hoole, where Horrocks made that first observations, there is much excitement.
Intrigued villagers join academics to watch the last moments of the transit.
Venus was due to quit the stage at 12.23 and 28 seconds.
But we miss her exit - a thin veil of clouds brings the curtain down unpredictably early.
Nature, it seems, is not ready to concede everything to the scientist just yet.