Nature Magazine – November 29, 2023: The latest issue cover features trails left by satellites, including BlueWalker 3, a prototype communications satellite, as they pass across the sky.

‘Early dark energy’ fails to solve mystery of cosmic expansion

The extra ingredient would explain why the Universe is expanding so fast now — but conflicts with data from ancient quasars.

Huge California wildfires seeded cirrus clouds half a world away

Smoke from record-breaking fires in 2020 travelled all the way to Cyprus, where it helped to trigger cloud formation.

These falcons excel at problem-solving — and outdo some of the world’s smartest birds

A bird of prey called the striated caracara can figure out puzzles that are a struggle for Goffin’s cockatoos, which are known for their intelligence.