Strange signal detected from planet outside our solar system for first time
Astronomers have detected a strange radio signal from a planet outside the solar system for the first time, indicative of the presence of a strong magnetic field around the world of over a thousand times stronger than Earth's.
The signal came from Beta Pictoris b, a young planet about 64 light-years away, say researchers from the Harvard-Smithsonian Centre for Astrophysics.
It likely came from the exoplanet's aurora, similar to the phenomenon that produces northern and southern lights on Earth.
The space weather phenomenon is caused by electrically charged molecules colliding with a planet's magnetic field, exciting the molecules. The excited molecules emit light and glow as they return to their normal states.
"Here, we report the first direct detection of auroral radio emission from an exoplanet, the giant planet β Pictoris b," scientists wrote in a yet-to-be peer-reviewed study detailing the discovery.
"Although auroral radio bursts are observed in Solar System planets and in some ultracool dwarfs, no radio detection has previously been unambiguously localised to an extrasolar planet rather than its host star," they explained.
Artist's impression shows how the planet inside the disc of Beta Pictoris may look (ESO/L. Calçada)
The discovery was made by astronomers surveying space using South Africa's MeerKAT array.
Researchers observed the Beta Pictoris system four times in 2025 and 2026.
It is a gas giant about 12 times Jupiter's mass, orbiting its host star at roughly Saturn's distance from the Sun.
Each time MeerKAT scientists observed the planet, they detected short bursts of strong radio signals that faded rapidly.
By comparing the radio signal's position with the precisely known locations of its host star and nearby planets, researchers could confirm that the strange signals indeed came from Beta Pictoris b.
They found that the signals propagated in space in a characteristic circular orientation, the same way radio waves from auroras travelled.
Even if Jupiter's diameter is ten times larger than the Earth's, this illustration shows the similarities between the two kinds of aurora (Nasa)
The signal's strength also reached the top of MeerKAT's observing band, suggesting that the planet's magnetic field strength was likely over 1,250 Gauss (1.25kG) – the unit of magnetism.
In comparison, Earth's magnetic field strength at its surface is about 0.5 Gauss.
It is not a surprise the planet with a mass 10 times that of Jupiter would produce such a strong magnetic field.
However, the discovery itself marks the first time scientists could isolate radio signals from a planet from its surrounding companions, and trace them to the planet's magnetic field.
The magnetic field of over 1.25kG at the planet is "the first such direct field strength measurement for an exoplanet", scientists wrote.
"This result, if it holds up in peer review, is an incredibly exciting advancement...It would be a fantastic result," astronomer Joe Callingham of the University of Amsterdam, who was not involved in the study, told Science News.