Since its launch in 1997, the Cassini spacecraft has traveled more than 3.85 billion miles. It has sent back 450 gigabytes of data, including more than 300,000 images of stormy Saturn, its majestic rings, and its rich and complicated system of moons. But perhaps the most notable number of the mission is 1: That is how many people oversee the creation of what may well be the most remarkable photo album ever assembled.
Carolyn Porco is the one. As the leader of the imaging science team on the Cassini mission to Saturn, she oversees collection and analysis of all the high-resolution pictures the spacecraft sends home. She has also done more than anyone else to spread interest in Saturn and its intricately beautiful rings and moons. She shares Cassini’s discoveries with the public through a website and in regular emails to thousands of devoted followers. Her exploratory zeal comes through on her website, where entries begin, in guileless Star Trek style, “Captain’s Log.”
Looking through Cassini’s eyes, Porco has gazed at Saturn’s ring system, where untold trillions of particles jostle and collide, giving rise to eerie gaps, spokes, and shifting pileups. She has witnessed a 180,000-mile-long storm erupt across Saturn’s pale yellow atmosphere, encircling the planet and crackling with blue lightning. She was there as Cassini discovered lakes of liquid methane and ethane dotting the poles of Saturn’s giant moon Titan, which is larger than the planet Mercury.
And in perhaps the mission’s greatest surprise, Porco saw bright jets of water, tinged with organic chemicals, shooting from Saturn’s Colorado-size moon Enceladus. Once dismissed as a dreary, inert ball of ice and rock, it is now considered one of the most likely places in the solar system to find life. “I’m writing a paper on Enceladus, and it’s going to be one kick-ass paper,” Porco exults. “The geysering on Enceladus is the most astonishing phenomenon we have in our solar system.”