Joel Achenbach The Washington Post

Before the slaughter of dozens of people in Christchurch, New Zealand and El Paso, Texas this year, the accused gunmen took pains to explain their fury, including their hatred of immigrants. The statements that authorities think the men posted online share another obsession: overpopulation and environmental degradation.

Like chess, checkers, Go and other games, the most popular form of poker has now been mastered by the cold, heartless machinations of a computer program.

Jason Les, one of the world's premier poker players, was representing his species when he faced off in May against a computer program named Pluribus. The game was multiplayer no-limit Texas hold 'em.

To put astronauts on the surface of the moon and bring them home safely, NASA had to do many things right, in succession, with margins of error ranging from small to nonexistent.

Neil Armstrong and Edwin Aldrin walked on the moon, gathered rocks, planted a flag, rocketed home to Earth and splashed down safely in the Pacific Ocean. After three weeks in quarantine (to prevent a purely hypothetical moon-germ contagion), the three Apollo 11 astronauts got their ticker-tape parade and eternal glory.

Archaeologists have dug up evidence that people were catching a cannabis buzz way, way before Woodstock, before the Summer of Love and even before there were jazz clubs or alarmist movies warning of "Reefer Madness."

Astronaut Scott Kelly made himself a guinea pig for all the people who dream of human journeys to Mars and other destinations in space. In 2015, Kelly rode a rocket into space and spent nearly a year on the International Space Station in low Earth orbit, while his identical twin brother, Mark Kelly, stayed on Earth's surface for NASA's celebrated "...

Scientists have finally captured the first direct image of a supermassive black hole.

The Event Horizon Telescope is a network of 10 radio telescopes on four continents that collectively operate like a single instrument nearly the size of the Earth.

At precisely 13:00 Universal Time on Wednesday - 9 a.m. in the Eastern United States - scientists will hold simultaneous news conferences in Washington, D.C., Belgium, Denmark, Chile, Japan, China and Taiwan to reveal the long-awaited results of the Event Horizon Telescope. What everyone is expecting and hoping to see is the first direct image of a...

President Donald Trump sent out a pre-dawn tweet Saturday boasting about Trump International Golf Links, constructed near Aberdeen, Scotland, among the high, wind-raked dunes along the North Sea.

On June 30, 1908, an object the size of an apartment building came hurtling out of the sky and exploded in the atmosphere above Siberia. The Tunguska event, named for a river, flattened trees for 800 square miles.

Fifty years later, it's hard to remember how mind-blowing Apollo 8 was, and how scary.

College professor Jeff McClenahan hiked up a winding road Saturday toward a terrible unknown, expecting the worst.

California is on fire again, north and south, the flames deadly and swift, fanned by ferocious Santa Ana winds and fueled by dry tinder. The fires have killed at least nine people, immolated a mountain town and jangled the nerves of many tens of thousands of residents forced to evacuate their homes.

Before the slaughter of dozens of people in Christchurch, New Zealand and El Paso, Texas this year, the accused gunmen took pains to explain their fury, including their hatred of immigrants. The statements that authorities think the men posted online share another obsession: overpopulation and environmental degradation.

Like chess, checkers, Go and other games, the most popular form of poker has now been mastered by the cold, heartless machinations of a computer program.

Jason Les, one of the world's premier poker players, was representing his species when he faced off in May against a computer program named Pluribus. The game was multiplayer no-limit Texas hold 'em.

To put astronauts on the surface of the moon and bring them home safely, NASA had to do many things right, in succession, with margins of error ranging from small to nonexistent.

Neil Armstrong and Edwin Aldrin walked on the moon, gathered rocks, planted a flag, rocketed home to Earth and splashed down safely in the Pacific Ocean. After three weeks in quarantine (to prevent a purely hypothetical moon-germ contagion), the three Apollo 11 astronauts got their ticker-tape parade and eternal glory.

Archaeologists have dug up evidence that people were catching a cannabis buzz way, way before Woodstock, before the Summer of Love and even before there were jazz clubs or alarmist movies warning of "Reefer Madness."

Astronaut Scott Kelly made himself a guinea pig for all the people who dream of human journeys to Mars and other destinations in space. In 2015, Kelly rode a rocket into space and spent nearly a year on the International Space Station in low Earth orbit, while his identical twin brother, Mark Kelly, stayed on Earth's surface for NASA's celebrated "...

Scientists have finally captured the first direct image of a supermassive black hole.

The Event Horizon Telescope is a network of 10 radio telescopes on four continents that collectively operate like a single instrument nearly the size of the Earth.

At precisely 13:00 Universal Time on Wednesday - 9 a.m. in the Eastern United States - scientists will hold simultaneous news conferences in Washington, D.C., Belgium, Denmark, Chile, Japan, China and Taiwan to reveal the long-awaited results of the Event Horizon Telescope. What everyone is expecting and hoping to see is the first direct image of a...

President Donald Trump sent out a pre-dawn tweet Saturday boasting about Trump International Golf Links, constructed near Aberdeen, Scotland, among the high, wind-raked dunes along the North Sea.

On June 30, 1908, an object the size of an apartment building came hurtling out of the sky and exploded in the atmosphere above Siberia. The Tunguska event, named for a river, flattened trees for 800 square miles.

Fifty years later, it's hard to remember how mind-blowing Apollo 8 was, and how scary.

College professor Jeff McClenahan hiked up a winding road Saturday toward a terrible unknown, expecting the worst.

California is on fire again, north and south, the flames deadly and swift, fanned by ferocious Santa Ana winds and fueled by dry tinder. The fires have killed at least nine people, immolated a mountain town and jangled the nerves of many tens of thousands of residents forced to evacuate their homes.