For the first time ever, a radio emission from a planet outside of our Solar System has been detected. While this doesn’t mean we’ve found the presence of extraterrestrial life, it still marks a big step in the study of exoplanets’ magnetic fields, which could be key in discerning whether they have atmospheres.
A new preprint paper on arXiv announced the detection of a radio emission coming from Beta Pictoris b, a massive exoplanet located about 63 light-years from Earth. Based on this emission, astronomers have calculated the exoplanet’s magnetic field strength, finding that Beta Pictoris b boasts a much stronger magnetic field than Earth and the giant planets in our Solar System.
This discovery is only the beginning, as investigating the magnetic fields of other exoplanets may reveal how some planets are protected from cosmic radiation — a key property that could provide insight in the search for life beyond Earth.
Read More: Earth's Magnetic Field May Influence Aging by Affecting How Mitochondria Produce Energy
A Massive Super-Jupiter
Beta Pictoris b is one of three known exoplanets orbiting the star Beta Pictoris, which is estimated to be 21 million years old, or less than 1 percent the age of our Solar System, according to NASA.
Explore All OptionsThe young gas giant exoplanet’s mass is somewhere around 9 to 13 times that of Jupiter’s mass, making it a “super-Jupiter.”
Massive exoplanets like Beta Pictoris b generally serve as promising targets in the search for radio emissions; according to a 2023 arXiv paper, massive planets are more likely to have strong magnetic fields, which leads to better chances of detecting their radio emissions. This likely has something to do with the dynamo of said planets, or the movement of electrically conductive fluid inside them, generating their magnetic fields.
Tracking Down a Radio Signal
Although massive exoplanets could be crucial in the search for radio emissions, astronomers have had trouble in the past knowing whether a specific emission is coming from an exoplanet or its host star.
The Beta Pictoris system, however, was considered ideal for searching for an exoplanet radio emission because its star is magnetically quiet. In addition, Beta Pictoris b is the most massive planet in the system.
Researchers observed the Beta Pictoris system with MeerKAT, an array of telescopes in South Africa, on four occasions between 2025 and 2026, detecting an auroral radio emission coming from the system; this signal comes from a planet’s aurora, which stems from electrons moving along magnetic field lines (on Earth, this is what creates phenomena like the Northern Lights).
The researchers needed to figure out the precise source of the radio emission — either one of the three exoplanets or the host star. To do so, they determined the exact positions of the star and planets by using the positions of quasars as a reference.
After this, they tied the radio image that they initially captured to the positions of the star and exoplanets, discovering that the true source of the radio emission was Beta Pictoris b.
The Significance of a Strong Magnetic Field
The researchers used the radio emission discovery to estimate the strength of Beta Pictoris b's magnetic field. They calculated a magnetic field strength of at least 1,250 gauss; this is far stronger than Jupiter's magnetic field, which has a gauss of 4.3, and Earth's magnetic field, which is only around half a gauss strong, according to Arizona State University.
While Beta Pictoris b doesn't host life, other exoplanets that may be habitable would potentially benefit from having a magnetic field, as it could help them maintain an atmosphere. As a result, searching for similar radio emissions from rocky, Earth-like exoplanets could end up being a critical step in the search for extraterrestrial life.
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Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a preprint study published in arXiv: Discovery of radio emission from the exoplanet β Pictoris b
- This article references information from NASA: Virtual Beta Pictoris
- This article references information from a study published in arXiv: On the required mass for an exoplanet to emit radio waves
- This article references information from Arizona State University: Astronomers make first calculations of magnetic activity in 'hot Jupiter' exoplanets
