Magazine

Science

Why does a gravitational lens sometimes create an Einstein Cross with four images and sometimes a circle?

Observing

Evening planet show

Observing

Exploring Pegasus

Cosmology

If tachyons exist, how might they be detected?

Astrophotography

Variable stars

Observing, The Moon

The Super-Ultra HyperMoon

Science

The quandary of predictability

Observing

Sweet autumn binaries

Robotic Spaceflight, Science, Solar System

How will the landings, takeoffs, and investigative explosions from the OSIRIS-REx and Hayabusa2 spacecraft alter the orbital paths of asteroids Bennu and Ryugu? Can these effects be equated to a duration of sunlight falling on each asteroid?

Science

Waiting for Skynet

Observing

Light from distant stars

Science

If our Sun is a typical star, and if most stars are surrounded by Oort clouds, why do these clouds not obscure our view of other stars?