A Century-Old Cosmic Mystery Solved – Four Hidden Planets Found Near Earth

Astronomers have confirmed the existence of four rocky planets orbiting Barnard’s Star, our nearest solitary stellar neighbor just six light-years away.

Using ultra-sensitive instruments, scientists detected subtle wobbles in the star’s light caused by the gravitational pull of these tiny worlds, each far smaller than Earth. These signals were buried under a noisy background of stellar jitters, but through advanced modeling and precise data analysis, researchers were able to separate the planet from the star.

A New Planetary Family Next Door

Astronomers have discovered four rocky planets, all significantly smaller than Earth, orbiting Barnard’s Star — the closest single star to our Sun and second closest overall, after the Alpha Centauri system.

Barnard’s Star is located just six light-years away and has a long history of false alarms when it comes to planet detection. But this time, the evidence looks solid. Thanks to advanced, high-precision instruments, researchers have confirmed the presence of four tiny planets. Finding such small worlds is no easy task, especially at this distance, and makes the discovery all the more impressive.

How Small Worlds Reveal Themselves

Scientists used a technique called radial velocity, which looks for tiny wobbles in a star’s light caused by the gravitational pull of orbiting planets. The smaller the planet, the weaker the signal, and these four planets are only about one-fifth to one-third the mass of Earth.

Complicating matters, stars like Barnard’s naturally shake and shimmer, creating “noise” that can drown out the faint signals from small planets. In this case, the planetary signals were extremely subtle, causing shifts of just 0.2 to 0.5 meters per second, slower than a human walking pace. Meanwhile, the background noise from the star’s activity was nearly 10 times greater, around 2 meters per second.

Separating those faint planetary whispers from the stellar noise took advanced modeling and cutting-edge technology, a quiet triumph in the ongoing search for worlds beyond our solar system.

Sharpening the Cosmic Picture

How do we separate planet signals from stellar noise? The astronomers made detailed mathematical models of Barnard’s Star’s quakes and jitters, allowing them to recognize and remove those signals from the data collected from the star.

The new paper confirming the four tiny worlds — labeled b, c, d, and e — relies on data from MAROON-X, an “extreme precision” radial velocity instrument attached to the Gemini Telescope on the Maunakea mountaintop in Hawaii. It confirms the detection of the “b” planet, made with previous data from ESPRESSO, a radial velocity instrument attached to the Very Large Telescope in Chile. And the new work reveals three new sibling planets in the same system.

Too Hot to Host Life, but Full of Promise

These planets orbit their red dwarf star much too closely to be habitable. The closest planet’s “year” lasts a little more than two days; for the farthest planet, it’s is just shy of seven days. That likely makes them too hot to support life. Yet their detection bodes well in the search for life beyond Earth. Scientists say small, rocky planets like ours are probably the best places to look for evidence of life as we know it. But so far they’ve been the most difficult to detect and characterize. High-precision radial velocity measurements, combined with more sharply focused techniques for extracting data, could open new windows into habitable, potentially life-bearing worlds.

Barnard’s star was discovered in 1916 by Edward Emerson Barnard, a pioneering astrophotographer.

Behind the Discovery

An international team of scientists led by Ritvik Basant of the University of Chicago published their paper on the discovery, “Four Sub-Earth Planets Orbiting Barnard’s Star from MAROON-X and ESPRESSO,” in the science journal, The Astrophysical Journal Letters, in March 2025. The planets were entered into the NASA Exoplanet Archive on March 13, 2025.

Explore Further: After 100 Years of Searching, Astronomers Confirm Four Planets at Barnard’s Star

Reference: “Four Sub-Earth Planets Orbiting Barnard’s Star from MAROON-X and ESPRESSO” by Ritvik Basant, Rafael Luque, Jacob L. Bean, Andreas Seifahrt, Madison Brady, Lily L. Zhao, Nina Brown, Tanya Das, Julian Stürmer, David Kasper, Rohan Gupta and Guđmundur Stefánsson, 11 March 2025, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/adb8d5

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