Scientists detect radio signals coming directly from an exoplanet for the first time

Radio signals coming directly from an exoplanet have been detected for the very first time.Astronomers used the massive MeerKAT radio telescope array in South Africa to spot short, repeating bursts of radio waves.Using bright galaxy cores called quasars as reference points, the scientists were able to pin down this signal's origin to a single planet 63.4 light-years from Earth.However, the researchers say this isn't an alien civilisation trying to send us a message.Instead, the signal is coming from the exoplanet's auroras, created by charged particles from its parent star interacting with the magnetic field.On Earth, these same effects create the dazzling Northern Lights, but no one has been able to pick up the signal of an alien aurora outside the solar system before now.In their pre-print paper, the researchers write: 'Although auroral radio bursts are observed in Solar System planets and in some ultracool dwarfs, no radio detection has previously been unambiguously localized to an extrasolar planet rather than its host star.' Radio signals coming directly from an exoplanet, a planet outside the solar system, have been detected for the very first time (illustrated) Astronomers used the massive MeerKAT radio telescope array in South Africa to spot short, repeating bursts of radio waves (illustrated) On four separate occasions in 2025 and 2026, scientists focused their radio telescopes on the distant star Beta Pictoris.Previous studies have found that this star is home to four orbiting exoplanets, named Beta Pictoris a, Beta Pictoris b, Beta Pictoris c and Beta Pictoris d.Although scientists have detected powerful radio bursts from the solar system, it has previously been immensely difficult to filter out any planetary signals from the noise of a nearby star.However, the particular type of star and radio signal the astronomers found made this fine separation possible for the first time.The radio signal was highly circularly polarised, which is a classic signature of a signal emitted by a planet's aurora.Beta Pictoris is also an 'early–type star', meaning it is larger, hotter, and structured differently from stars like our sun.However, these types of stars are incapable of producing the kinds of radio signals the researchers were seeing.The authors wrote: 'No physical mechanism known to cause radio emission in early–type stars can explain the observed emission.'That means the radio signal must be coming from one of the orbiting exoplanets, rather than the star itself. The signals were traced back to Beta Pictoris b, a massive gas giant orbiting a star 63.4 light–years from Earth Beta Pictoris is home to four exoplanets, including Beta Pictoris b, which became the faintest exoplanet ever to be directly imaged last year (pictured)Using the bright reference points of quasars, the scientists finally found that the signal was being emitted by Beta Pictoris b, the second planet out from the star.Previous studies have shown that Beta Pictoris b is a young, massive gas giant, about 10 times the mass of Jupiter.What makes this discovery so exciting is that it opens up a new avenue for understanding the makeup of exoplanets.Beta Pictoris b's aurora is produced by an effect called Electron Cyclotron Maser Instability, which is the same process that creates the stunning auroras on planets like Jupiter and Mars.Since scientists have a good understanding of how this effect works, they can use the radio signals it produces to make predictions about the planet itself.Using their new measurements, the researchers were able to show that Beta Pictoris b has an incredibly strong magnetic field, thousands of times more powerful than Earth's.These signals are further boosted by the planet's rapid rotation, with the researchers estimating that days on Beta Pictoris b only last eight to nine hours.While it might be disappointing that these signals don't come from an alien race, insights like these could be key to finding life beyond our solar system one day.A planet's magnetic field insulates the surface from harmful radiation that would destroy early life and helps hold the atmosphere together against the ravages of solar wind.If astronomers can isolate aurora signals from exoplanets, they can also figure out which planets are most likely to have conditions favourable for life.The researchers already have plans to use their new techniques on seven other exoplanets located in five solar systems.These planets could soon be analysed in the same way as Beta Pictoris b, with planned next-generation radio observatories making even more sensitive observations possible.Scientists study the atmosphere of distant exoplanets using enormous space satellites like Hubble Distant stars and their orbiting planets often have conditions unlike anything we see in our atmosphere. To understand these new world's, and what they are made of, scientists need to be able to detect what their atmospheres consist of. They often do this by using a telescope similar to Nasa's Hubble Telescope.These enormous satellites scan the sky and lock on to exoplanets that Nasa think may be of interest. Here, the sensors on board perform different forms of analysis. One of the most important and useful is called absorption spectroscopy. This form of analysis measures the light that is coming out of a planet's atmosphere. Every gas absorbs a slightly different wavelength of light, and when this happens a black line appears on a complete spectrum. These lines correspond to a very specific molecule, which indicates it's presence on the planet. They are often called Fraunhofer lines after the German astronomer and physicist that first discovered them in 1814.By combining all the different wavelengths of lights, scientists can determine all the chemicals that make up the atmosphere of a planet. The key is that what is missing, provides the clues to find out what is present. It is vitally important that this is done by space telescopes, as the atmosphere of Earth would then interfere. Absorption from chemicals in our atmosphere would skew the sample, which is why it is important to study the light before it has had chance to reach Earth. This is often used to look for helium, sodium and even oxygen in alien atmospheres. This diagram shows how light passing from a star and through the atmosphere of an exoplanet produces Fraunhofer lines indicating the presence of key compounds such as sodium or helium