Astrophysics
Giant Galaxies from the Universe's Childhood Challenge Cosmic Origin Stories
Large galaxies are thought to form gradually, across billions of years of cosmic time. So why do astronomers keep finding them in the youthful early universe?
Features
Space & Physics
Telescopes on Far Side of the Moon Could Illuminate the Cosmic Dark Ages
Instruments deployed on missions to the lunar far side might give us an unprecedented view of the early universe
Space & Physics
Astronomer Avi Loeb Says Aliens Have Visited, and He's Not Kidding
In conversation, the Harvard University professor explains his shocking hypothesis—and calls out what he sees as a crisis in science
Departments
- From the Editor
Onward, Intrepid Rover
- News
Perseverance Has Landed! Mars Rover Begins a New Era of Exploration
The First 100 Days on Mars: How NASA's Perseverance Rover Will Begin Its Mission
Galaxy-Size Gravitational-Wave Detector Hints at Exotic Physics
Is It a Planet? Astronomers Spy Promising Potential World around Alpha Centauri
Mystery of Spinning Atomic Fragments Solved at Last
Quantum Network Is Step Toward Ultrasecure Internet
- Opinion
Until Recently, People Accepted the 'Fact' of Aliens in the Solar System
Quantum Mechanics, Free Will and the Game of Life
Did a Supermassive Black Hole Influence the Evolution of Life on Earth?
Physicists Need to Be More Careful with How They Name Things
