Astronomers using the MeerKAT telescope have detected the first direct radio signal from an exoplanet, Beta Pictoris b, located 63 light-years from Earth.

The signal is believed to come from auroras, similar to the northern lights on Earth. It is the first time radio waves from a planet beyond our solar system have been picked up directly.

Scientists stressed the signal is natural, not a sign of alien life. Auroral radio emissions are produced when charged particles interact with a planet's magnetic field.

The detection was reported in a preprint published on September 15. It opens a new way to study exoplanet magnetic fields, which are otherwise very hard to measure.

A planet's magnetic field can shield its atmosphere from stellar winds, a factor in whether it could support life. Measuring such fields has long been a goal of astronomers.

The team hopes to detect similar signals from more exoplanets as radio telescopes grow more sensitive.