In April, Cassini will shift its orbit again to slice between the planet and the rings, sneaking as close as 1,012 miles from the clouds of Saturn in 22 more orbits. Finally, on Sept. 15, at 8:07 a.m., Earth time in New York, the spacecraft will crash into the clouds of Saturn and burn up.

Science will never be the same. Nor will Saturn, now forever polluted by a few stray atoms from the blue planet. Thereafter, there will always be a little piece of Earth on Saturn.