A strange double flash in a distant galaxy may be the first glimpse of a “superkilonova,” a cosmic one‑two punch that fuses ...

A strange flash in a distant galaxy first looked like a familiar kind of stellar wreckage, the radioactive afterglow of ...

Scientists using the James Webb telescope observed a distant exoplanet with an atmosphere of soot and diamonds, challenging ...

Amid all of io9’s lists looking back at the year’s best books, movies, TV shows, and more, there’s always one melancholy ...

From an interstellar comet to breathtaking auroras and from brand-new rockets to iconic space telescopes, here are some of our favorite images from the cosmos in 2025 ...

One of the oldest unsolved riddles in planetary science concerns the origin of the moon. Over a century ago, George Darwin proposed that tidal and centrifugal forces on a rapidly rotating proto-Earth ...

In this scenario, our first contact with aliens would be tragic. We should look for "loud shouts in the night".

Andersen Genève’s Communication 45 world timer is an outright showstopper. The heat-tempered gold dial, recessed map and ...

A double blast of dying stars may be the first observed case of a long-hypothesized, never proven “superkilonova.” Although ...

A distant neutron star unexpectedly reawakened, unleashing a powerful X-ray surge that may reveal how the universe’s most ...

Describing matter under extreme conditions, such as those found inside neutron stars, remains an unsolved problem. The ...

A massive star may have burst, leaving behind two dense, dead cores, which then collided and caused another explosion ...