About 85 percent of all the matter in the universe appears to be dark matter. Yet scientists haven’t been able to find it. But a recent study suggests a new way to look for it: by taking the temperature of many planets in other star systems.

Dark matter almost never interacts with everyday matter — the stuff that makes up stars, planets, and people. But astronomers know it’s there because it exerts a gravitational pull on the stars and galaxies around it.

Dark matter is thought to be made of subatomic particles. But every effort to find them has come up empty. So astronomers recently said that we might see them indirectly in planets near the center of the galaxy.

There should be more dark matter concentrated there than in the galactic suburbs, where we are. Some of the dark matter should interact with matter in the centers of planets. If the planets are comparable to Jupiter, the giant of our own solar system, then there could be enough interactions to make the planets hotter. So taking the temperature of giant planets across the galaxy could tell us whether dark matter really does consist of tiny particles — and what those particles are like.

Such a project would need to study more planets than we know about. But future ground- and space-based telescopes should find many more. They should also be able to measure the temperatures of those planets — perhaps helping to solve the mystery of dark matter.

Script by Damond Benningfield

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