Was it a cosmic jellyfish, a fleeting light trick, or something more outlandish? When NASA astronaut Nichole Ayers took a ...

Tissue samples sent to the International Space Station reveal what can happen to astronauts on long-term missions.

How do we know 3I/ATLAS, also called comet C/2025 N1 (ATLAS), is interstellar? Will it strike Earth? Can we visit it? Here ...