A colossal cosmic thread has been mapped, revealing the universe’s largest known rotating structure to date. Researchers have identified a vast, filament-like assembly that threads together hundreds of galaxies, intergalactic gas, and dark matter within the cosmic web—the immense network that structures the cosmos.
Located about 140 million light-years away, this rotating filament was primarily detected with the MeerKAT radio telescope in South Africa, an array of 64 interconnected dishes. The feature spans roughly 50 million light-years in length and about 117,000 light-years across. To put that in perspective, a light-year represents the distance light travels in a year, about 5.9 trillion miles (9.5 trillion kilometers). Our Milky Way, itself part of a cosmic filament, measures around 100,000 light-years in diameter.
Madalina Tudorache, a Cambridge astrophysicist who co-led the study published in Monthly Notices of the Royal Astronomical Society, explains that the universe on vast scales forms a network of galaxies, gas, and dark matter. This cosmic web comprises dense clusters where matter clumps together, vast voids that are largely empty, and filaments that connect these dense regions and outline the voids.
The rotating filament in this research hosts nearly 300 galaxies of varying sizes, along with gas and dark matter—the unseen substance thought to constitute about 27% of the universe.
Ordinary matter—the stars, planets, moons, and everything visible—emits or reflects light across infrared to gamma-ray wavelengths, but it accounts for only about 5% of the cosmos. Dark matter, invisible to light, reveals itself through its gravitational influence on cosmic structures.
By tracking the motion of galaxies on opposite sides of the filament’s central axis, the team concluded that the filament is in rotation, with a rotational speed around 246,000 miles per hour (approximately 396,000 kilometers per hour).
Lyla Jung of Oxford, another co-lead author, notes that this finding marks the largest single spinning structure detected so far. While the cosmos likely contains other spinning filaments—some potentially larger—the current data and telescope capabilities have prevented direct observations of those cases yet.
To illustrate the phenomenon, researchers compare the filament to a teacup ride at an amusement park. Each galaxy spins on its own axis, with gas and stars circling within each galaxy just as the individual teacups rotate. At the same time, the entire filament—the collective assembly of many galaxies—rotates as a whole, much like the teacup platform turning around.
Astrophysicists examine the universe across scales—from the tiniest particles, such as neutrinos, to individual bodies like comets and planets, up to galaxies and clusters, and finally to the vast filaments of the cosmic web. This study emphasizes the largest end of that spectrum.
Tudorache emphasizes that this era is exceptionally exciting for the field, as advances in radio and optical surveys are boosting our ability to discover such immense structures. These observations promise to deepen our grasp of how the universe is organized and evolves.
Reporting was led by Will Dunham and edited by Daniel Wallis."
