These Chimps Began the Bloodiest ‘War’ on Record. No One Knows Why.

A long-running conflict in a Ugandan park may provide clues to the origins of human warfare, and how to avoid it.

By Carl Zimmer

Global Wildlife Trade Fuels Spread of Disease From Animals to People

Live animal markets and the illegal sale of wildlife pose particular dangers, but any sale of wild animals or animal products poses spillover risks, a new study suggests.

By Emily Anthes

Trilobites

For Ants, a ‘Cleaning Station’ in the Desert

A unique “choreography” between two ant species suggests a distinctive partnership in which one provides a carwash service to the other.

By Alexa Robles-Gil

Eyes on the Far Side of the Moon

See the photos taken by the Artemis II astronauts during their moon flyby.

By Marco Hernandez

In Photos and Video

Artemis II’s New Views of the Moon

Over 10 days, the astronauts of NASA’s lunar flyby mission have achieved the near impossible.

By The New York Times

What’s Inside NASA’s Mission Control

Take a tour of the room where the team behind Artemis II is working to bring the astronauts home.

By Marco Hernandez, Malika Khurana and Katrina Miller

Artemis II Crew Reunites With Families and Fellow NASA Astronauts

The four astronauts made an emotional return to Houston a day after splashing down in the Pacific Ocean at the end of their 10-day lunar journey.

By Kenneth Chang

Artemis II Splashdown Gives NASA Momentum in Renewed Moon Race

The astronauts — three Americans and one Canadian — captivated the world with their historic mission.

By Kenneth Chang

How Lee Zeldin Shifted the Mission — and the Message — of the E.P.A.

More than any administrator in decades, Lee Zeldin talks about the Environmental Protection Agency's work in economic terms, reflecting President Trump’s desire to boost industry while downplaying environmental consequences.

By Lisa Friedman and Harry Stevens

Climate Change Denial Sees a Resurgence in Trump’s Washington

A conference near the White House drew hundreds of people who reject the scientific consensus on climate change. The mood was triumphant.

By Maxine Joselow

Heat Wipes Out Western Snowpack, Raising Fears of Drought, Wildfire

A record-mild winter and blistering spring heat will mean higher risks of water shortages and wildfires in the months ahead.

By Scott Dance, Sachi Kitajima Mulkey and Mira Rojanasakul

How Psychedelics Affect the Brain

An analysis of hundreds of images from several studies shows how hallucinogenic drugs drive activity in various regions of the brain.

By Andrew Jacobs

Patients Are Using Chatbots to Fight Medical Bills, With Mixed Results

While chatbots like Claude and ChatGPT can help narrow the information divide between patients and providers, they can also dispense flawed advice.

By Sarah Kwon

He Warned About the Dangers of A.I. If Only His Father Had Listened.

Ben Riley was already writing about the risks of chatbots when his dad started trusting A.I. over his doctor.

By Teddy Rosenbluth