A probe sets out for Jupiter and Saturn

Despite its number, Voyager 2 departed before Voyager 1, beginning its journey to the outer planets.

Voyager 2 took a path that would later permit encounters with Jupiter, Saturn, Uranus and Neptune.

The spacecraft carried cameras and instruments to study planets, moons and their environments.

The probe’s record carried images and sounds selected to represent life and culture on Earth.

The second Voyager launch used a trajectory that overtook Voyager 2 on the way to Jupiter.

Its record presented sounds and images from Earth to any future finders of the spacecraft.

The 5 September launch completed the pair’s departure for outer-planet exploration.

Researchers compared thousands of dated observations with modern orbital calculations to study long-term changes in Earth's rotation.

A mismatch between predicted and recorded eclipse paths reveals accumulated changes in the length of the day.

Records reaching back many centuries give modern science a time span impossible to reproduce with recent instruments alone.