Rafael Rebolo

Seven hours: that's how long a year lasts on TOI-4552b. It whips around its star faster than some moons orbit Earth. The star is a dim red dwarf, four times smaller than the Sun, but the planet is so close that it receives hundreds of times more heat than we do.

In 2034, a rocket leaves a spaceport with an unusual payload: two spheres the size of a large globe, each weighing nearly a ton. No engines, no electronics. Just a mirrored surface of hundreds of corner-cube reflectors — tiny prisms that return light exactly to where it came from. This is the future space tuning fork.

Imagine three witnesses who saw the same event. Two tell the same story, the third tells a different one. Whom do you believe? This is exactly the situation in astronomy when measuring carbon in the star J0815+4729, an ancient object with a record-low iron abundance (carbon is one of the key elements used to infer the properties of the…