A medical paper on smallpox was published in Boston, making it the first medical publication in American history.
Source
A meteorite that hit Australia 2.2 billion years ago was announced as Earth's oldest recognized meteorite impact structure.
Over two million women worldwide marched against Trump's anti-women and offensive slews.
The iconic DeLorean sports car began production in Northern Ireland.
Li Na became the first Asian-born tennis player to be entered into the International Tennis Hall of Fame.
America's Rocket Lab Electron sent a rocket that uses an electric-filled pump engine into orbit, making it the first of its kind.