Signal from the Void: NASA Spots Super-Earth That Has Been Whispering at Earth for Years
June 28, 2025 | Cape Canaveral, FL — Every 3.9 days the star TOI-1846 dims by 0.46 %—a change so small it equals covering a lighthouse bulb with a single postage stamp. Yet that faint flicker, logged 127 times since 2022 by NASA’s Transiting Exoplanet Survey Satellite (TESS), has now been decoded as a super-Earth 1.8 times wider and 4.1 times heavier than our own world. Stranger still, the same system is leaking an unexplained radio whisper that has shown up in archival data from the Very Large Array (VLA) for the past eight years.
Planet in the Desert
TOI-1846 b circles a cool, quiet red dwarf 154 light-years away in the constellation Cygnus. The planet’s radius—1.8 R⊕—places it inside the so-called radius gap, a near-empty band between 1.5 and 2.0 Earth radii where nature seems to skip a step. “It’s like finding a lone car parked on an eight-lane highway,” says Dr. Elisa Quintana, astrophysicist at NASA’s Goddard Space Flight Center. Follow-up observations with the Gemini-North telescope pinned its mass at 4.1 M⊕, yielding an average density of 5.8 g cm⁻³—rocky, but with room left for a thick atmosphere or a deep water envelope.The Signal That Shouldn’t Be There
While planet hunters were still crunching numbers, radio astronomers noticed something odd: a narrow-band emission at 74 MHz that peaks in strength only when the planet is closest to Earth in its orbit. The burst lasts 11 minutes, then vanishes. “We’ve ruled out flares from the star and interference from satellites,” explains Dr. Jayaram Chengalur of India’s National Centre for Radio Astrophysics. “The timing matches the planet’s year almost to the second.” One possibility is that TOI-1846 b hosts a magnetic field at least ten times stronger than Jupiter’s, turning its magnetosphere into a planetary-scale antenna.
Hot, Tidal-Locked, Maybe Wet
Because the planet hugs its star at one-tenth the Earth-Sun distance, daylight temperatures soar to 600 °F. Still, 3-D climate models suggest a thick CO₂ blanket could ferry heat to the permanent night side, allowing an annulus of twilight where water might pool. “Picture a lava lamp: molten rock on one face, snowfields on the other, and a narrow green belt in between,” says Quintana.
Because the planet hugs its star at one-tenth the Earth-Sun distance, daylight temperatures soar to 600 °F. Still, 3-D climate models suggest a thick CO₂ blanket could ferry heat to the permanent night side, allowing an annulus of twilight where water might pool. “Picture a lava lamp: molten rock on one face, snowfields on the other, and a narrow green belt in between,” says Quintana.
