The NASA space probe Mariner 9 becomes the first spacecraft to orbit another planet successfully when it begins circling Mars. Among the images it transmits back to Earth are photos of Olympus Mons, a volcano three times taller than Mount Everest and so wide at its base that, due to curvature of the planet, its peak would be below the horizon to a person standing on its outer slope.

British explorer Robert Falcon Scott and his men are found frozen to death on the Ross Ice Shelf in Antarctica, where they had been pinned down and immobilized by bad weather, hunger and fatigue. Scott's expedition, known as the Terra Nova expedition, had attempted to be the first to reach the South Pole only to be devastated upon finding that Norwegian explorer Roald Amundsen had beaten them there by five weeks. Scott wrote in his diary: "The worst has happened. All the day dreams must go. Great God! This is an awful place."

Hugh Gray takes the first known photos of the Loch Ness Monster while walking back from church along the shore of the Loch near the town of Foyers. Only one photo came out, but of all the images of the monster, this one is considered the most authentic.

Investigative journalist Seymour Hersh breaks the story of the My Lai massacre, which had occurred in Vietnam more than a year-and-a-half earlier but been covered up by military officials. That day, U.S. soldiers killed between 350 and 500 unarmed civilians, including women, the elderly, and infants. The event devastated America's image internationally and galvanized the U.S. anti-war effort. For Hersh's efforts he received a Pulitzer Prize.