Over the past decade, researchers have been puzzling through Pluto’s mysteries. Meanwhile, the New Horizons probe heads for interstellar space.

I/ATLAS might be over 7 billion years old, a new study reports, which would make it the oldest comet known. But experts caution we need more data.

Experiments in mice show that some gut bacteria can absorb toxic PFAS chemicals, allowing animals to expel them through feces.

Celina Zhao is a Summer 2025 science writing intern at Science News. She holds bachelor’s and master’s degrees in science writing from MIT. Previously, she interned at Science and NOVA.