The research team used the MeerKAT radio telescope array in South Africa. Photo credit: Artsiom P/Shutterstock
Imagine trying to work out what a planet is like when it is 63 light-years away, far beyond anything humans could visit. Astronomers have now found a way to measure one of its hidden features by detecting radio signals coming directly from the planet itself. The discovery could help scientists understand the magnetic fields of distant worlds, which are difficult to study using telescopes alone.
The signals came from Beta Pictoris b, a giant planet outside our Solar System. The finding might bring to mind the possibility of hearing from alien life, but there is no evidence of an extraterrestrial message. Researchers believe the radio bursts are linked to auroras generated by the planet’s magnetic field, similar in principle to the natural light displays seen around Earth’s poles. What makes the result unusual is that scientists were able to trace the radio emissions to the planet rather than its host star. Previous observations of radio waves from planetary systems have not always made it possible to distinguish between the two.
Radio waves traced to the planet itself
The research team used the MeerKAT radio telescope array in South Africa to observe the Beta Pictoris system. Across four observing sessions in 2025 and 2026, the researchers detected recurring bursts of radio waves at frequencies between 0.85 and 3.5 gigahertz. To work out where the emissions originated, the team compared its observations with the positions of distant quasars, extremely bright objects that can be used as reference points in the sky.
This helped the researchers separate the planet’s signal from the much brighter light of its star and identify Beta Pictoris b as the source. A radio signal detected from a distant planetary system does not automatically mean the planet produced it. By locating the source more precisely, the researchers have provided evidence that Beta Pictoris b is generating its own radio emissions.
A magnetic field far stronger than Earth’s
The radio waves also allowed the team to estimate the strength of the planet’s magnetic field. Their calculations suggest it measures at least 1,250 gauss at the point where the emissions are produced. Earth’s magnetic field is around half a gauss, making the estimated field at Beta Pictoris b vastly stronger. This is a lower limit at the emission site, rather than a measurement of the field across the entire planet. Earth’s magnetic field helps protect our planet from charged particles streaming from the Sun. On other planets, magnetic fields can also produce auroras and influence how their atmospheres interact with space.
The northern and southern lights appear when charged particles interact with gases in Earth’s upper atmosphere. Similar displays occur on giant planets such as Jupiter and Saturn, where magnetic activity also produces radio emissions. The researchers believe the bursts from Beta Pictoris b fit this type of auroral activity. The pattern and circular polarisation of the radio waves support that explanation, although more observations are needed to establish the source with greater certainty.
What is Beta Pictoris b
Beta Pictoris b is a young gas giant with a mass roughly 10 to 12 times that of Jupiter. It orbits a young star in a system that has attracted considerable attention from astronomers because its planets can be studied directly. Its size makes it a useful subject for investigating the magnetic fields of massive planets. Until now, scientists have largely relied on indirect methods and theoretical models when trying to understand magnetic fields beyond our Solar System.
If radio emissions can be used to estimate these fields on other exoplanets, researchers will have another way to compare distant worlds with planets closer to home. Magnetic fields influence how planets interact with charged particles released by their stars and can affect how material escapes from their atmospheres.
Further observations are needed
The findings were published on the arXiv preprint server in September this year. At the time of the initial reports, the research had not yet undergone peer review, and independent observations were needed to confirm the result. Further observations could help establish whether the radio bursts follow a pattern linked to the planet’s rotation and confirm whether auroral activity is responsible.
The same approach may also allow astronomers to investigate other giant planets beyond our Solar System. For researchers, the result offers a new way to investigate a feature of a distant planet that cannot be measured directly through ordinary images. By tracing the radio emissions to Beta Pictoris b, they have obtained an estimate of its magnetic field and opened up another way to study worlds far beyond our own.