August 20 in History

In 1977, NASA launched Voyager 2 and Voyager 1, two robotic spacecraft built to explore the outer solar system. Voyager 2 left Cape Canaveral, Florida, on August 20, and Voyager 1 followed on September 5, on a faster path. Together they became the first spacecraft to visit Uranus and Neptune, returned detailed images of Jupiter and Saturn, and went on to become the first human-made objects to enter interstellar space.

In August 2018, a fifteen-year-old Swedish schoolgirl named Greta Thunberg began sitting outside the Swedish parliament in Stockholm instead of attending class, holding a hand-painted sign that read "Skolstrejk för klimatet" ("School strike for climate"). What started as a solitary protest grew within months into a global youth movement, reshaping public debate about climate change and showing how a single individual's action could spread through social media and personal example.