Mars is currently inhabited by an estimated 1 million microbes. They coat the surfaces and crowd the innards of our robotic landers and rovers, which international policy requires…

Back in the day, before the speed of light was considered the slow lane, “extreme” sports—bungee jumping from bridges, hang gliding over volcanoes—were barely deadly and almost…

Let’s be optimistic and assume that we manage to avoid a self-inflicted nuclear holocaust, an extinction-sized asteroid, or deadly irradiation from a nearby supernova. That leaves…

No known object in existence has as clear a division between “inside” and “outside” as a black hole. We live and see the outside, and no probe will bring us information about…

The celestial object came flying across the nighttime sky quickly, moving in an unusual pattern. Chiara Mingarelli and her friend saw it from a field in rural Ontario, their regular…

It begins like a classic romance: Two black holes meet. The attraction is practically instant. They dance around each other, swirling closer and closer, until ... Until what? As with…

Like countless so-crazy-it-just-might-work schemes, this one began with a gripe session. In the fall of 2011, Roberto Abraham and Pieter van Dokkum were commiserating at a Nepalese…

With 2015 now behind us, what truly stands out? Other than (alas) holding the record for hottest year in recorded history? Amid a confusion of good, bad, and disturbing news, what…

Hot fluids of neutrons that flow without friction, superconductors made of protons, and a solid crust built of exotic atoms—features like these make neutron stars some of the strangest…

In the 1990s, during breaks from editing the film First Knight, starring Sean Connery, Walter Murch was reading The Sleepwalkers, a book on the history of cosmology, by the Hungarian-British…