Astronomers Discover 27 Mysterious Signals in Our Galaxy — Could Any of Them Be Aliens?

Something Keeps Flashing Across Our Galaxy

27 Mysterious Cosmic Signals Discovered Inside the Milky Way

Astronomers searching the radio sky have discovered 27 previously unknown transient sources inside our own galaxy. They appear, disappear and in some cases release isolated bursts separated by long stretches of silence, making them remarkably easy for conventional surveys to miss.

The obvious question is irresistible: what is producing them? And, given decades of speculation about strange signals from space, could anything artificial be involved? The scientific answer at present is much less exotic — but the discovery may still expose an enormous hidden population of objects scattered through the Milky Way.

Twenty-Seven New Sources Have Appeared in the Radio Sky

The discoveries come from MeerTRAP, a programme that searches observations from South Africa's powerful MeerKAT radio telescope for short radio pulses while the telescope is conducting other scientific work. Researchers reported the 27 new Galactic transients in a paper submitted on 12 August 2026.

Rather than behaving like continuously visible radio sources, these objects were detected through individual bursts. Researchers managed to pinpoint 14 of the discoveries to arcsecond-level precision by examining data preserved in a dedicated transient buffer.

For eight sources, multiple detected pulses allowed preliminary rotation periods to be calculated. Those periods range from roughly 0.78 seconds to four seconds.

That detail is enormously important because it begins to reveal what the objects probably are.

What Exactly Is a Rotating Radio Transient?

The researchers classify the objects as rotating radio transients, normally shortened to RRATs. These are generally understood to belong to the wider family of neutron stars — the extraordinarily dense remnants left after some massive stars explode.

A conventional pulsar rotates while directing beams of radio emission through space. If one of those beams repeatedly crosses Earth, radio telescopes detect an extraordinarily regular sequence of pulses.

RRATs are much more elusive. Instead of producing an easily detectable pulse during every rotation, they can remain apparently quiet for prolonged periods before suddenly producing an observable burst. Their intermittent behaviour means traditional pulsar surveys can overlook them even when they are sitting within the survey area.

That does not necessarily mean the object itself has stopped rotating. The telescope may simply detect very few of its radio pulses.

It is the cosmic equivalent of seeing a lighthouse flash once through heavy fog, then waiting without knowing when — or whether — the light will appear again.

Why Pulsars Are the Leading Explanation

The alien hypothesis immediately becomes far less persuasive once the signals are studied in detail.

Follow-up observations of the newly discovered objects found ordinary pulsar-like pulsed emission from four of them. The researchers also obtained coherent timing solutions for four sources, allowing their rotation to be modelled far more precisely.

This is exactly the direction astronomers would expect if at least some RRATs are not a completely separate category of object but rather part of a continuum of neutron-star behaviour.

That distinction is becoming increasingly blurred. Previous MeerTRAP discoveries have also shown how objects initially found through isolated pulses can later reveal much more conventional pulsar characteristics. A 2025 study reported 30 Galactic radio transient pulsars found through single-pulse searches, with most regarded as likely RRATs because of their unusually low detectable pulse rates.

Another census published in 2026 catalogued 335 RRATs and estimated that roughly 34,000 potentially observable RRATs above its adopted luminosity threshold could be beaming toward Earth.

Twenty-seven new discoveries therefore may represent only another glimpse of a population far larger than the objects astronomers have already catalogued.

Could Any of the Signals Be Artificial?

There is currently no evidence that any of the 27 signals were produced by extraterrestrial intelligence.

That qualification matters. “Unidentified” in astronomy does not mean “alien”, and a mysterious radio signal is not automatically a candidate technological transmission.

The measured rotation periods, repeated pulse behaviour and pulsar-like emission detected in follow-up observations all provide natural astrophysical explanations for these sources. The working interpretation places them within the neutron-star population rather than within the search for extraterrestrial technology.

Nor are these observations equivalent to the narrowband or otherwise technologically distinctive signals that SETI searches are often designed to investigate.

But asking whether an unexplained radio source could ultimately require a radically different explanation is not unscientific. Astronomy has repeatedly advanced by discovering things that initially did not fit existing categories.

The crucial difference is evidence.

At present, the evidence for these 27 sources points toward unusual stars, not alien transmitters.

Why the Alien Question Is Still Worth Asking Carefully

Radio astronomy occupies an unusual position in the search for extraterrestrial intelligence because radio waves are also one of humanity's most obvious methods of long-distance communication.

A sufficiently advanced civilisation could theoretically produce detectable radio emission. That possibility is one reason astronomers scrutinise strange radio signals rather than dismissing anomalies automatically.

But natural space phenomena are extraordinarily good at producing spectacular radio behaviour.

Pulsars themselves provide perhaps the perfect warning. When Jocelyn Bell Burnell and Antony Hewish's research group encountered the first pulsar signal in 1967, its extraordinary regularity was unusual enough for an extraterrestrial explanation to be considered privately before further pulsars established a natural stellar population.

The lesson was not that astronomers should never consider aliens.

It was that extraordinary regularity, unusual radio emission or an initially unknown source is not enough.

A genuinely persuasive technological candidate would need properties that are difficult to reproduce naturally and would need to survive repeated observations designed to eliminate terrestrial interference and astrophysical explanations.

Nothing published about these 27 sources has crossed that threshold.

The Bigger Mystery May Be How Many More Are Hiding

The genuinely exciting implication of this discovery is therefore different from the alien question.

Astronomers may still be substantially undercounting the neutron stars surrounding us.

MeerTRAP searches for individual pulses rather than relying entirely on the periodic signatures traditionally used to find pulsars. That gives it an advantage when an object emits so intermittently that its regular rotation is effectively hidden.

Previous MeerTRAP work has repeatedly expanded this hidden population. One study reported 26 new Galactic radio transients, another subsequently reported 30 new Galactic sources, and the new research adds another 27.

That does not mean every discovery represents exactly the same physical phenomenon. In fact, part of the scientific challenge is determining whether terms such as pulsar and RRAT describe genuinely different populations or merely different observational states of closely related neutron stars.

The latest discoveries reinforce that uncertainty because four objects initially appearing as transients later displayed more conventional pulsar-like emission.

The classification boundary itself may therefore be telling astronomers something important about neutron-star physics.

Why These Dead Stars Can Behave So Strangely

A neutron star packs roughly stellar-scale mass into an object only around the size of a city. It can rotate rapidly, possess an immense magnetic field and accelerate charged particles around its magnetic poles.

That extreme environment can generate tightly directed beams of electromagnetic radiation.

Yet researchers still do not have a complete description of why some neutron stars produce strong radio pulses continuously, why others switch between different emission states and why RRATs can remain apparently dormant before suddenly becoming visible.

This is why the new sample matters beyond simply increasing a catalogue from one number to another.

Each object gives astronomers another laboratory.

Its pulse frequency, burst rate, polarisation, rotation period, position and long-term evolution can all help determine whether intermittent objects occupy a distinct evolutionary phase or represent one extreme of normal pulsar activity.

And the more sources surveys discover, the harder it becomes for rare outliers to distort the picture.

Radio Astronomy Is Entering a Discovery Boom

The wider context may be even more important.

Modern wide-field radio telescopes are monitoring enormous regions of the sky with combinations of sensitivity, cadence and computing power that previous generations of astronomers simply did not possess.

That is beginning to expose phenomena which were effectively invisible to older observing strategies.

Long-period radio transients provide another example. Some produce pulses separated by minutes or even hours rather than the millisecond-to-second periods associated with conventional pulsars, creating an observational gap between techniques optimised for very fast pulses and those looking for changes over days or longer.

One extraordinary source, ASKAP J183950.5−075635.0, has been measured with a period of about 6.45 hours. Its characteristics were found to be consistent with a neutron-star origin despite sitting far outside the normal pulsar period range.

The implication is powerful.

The sky may not suddenly have become stranger.

Humanity may simply have become much better at watching it.

What Astronomers Do Next

The most important work now is repeated observation.

Four of the new sources already have coherent timing solutions, while eight have preliminary periods. Four revealing pulsar-like behaviour during follow-up demonstrates exactly why returning to these locations matters.

Researchers can now watch for additional pulses, refine rotation periods, measure how frequently individual sources become active and compare their behaviour against both conventional pulsars and previously known RRATs.

Better localisation also allows astronomers to search other wavelengths for anything associated with the radio source.

Every additional measurement removes possibilities.

That process may ultimately make these objects seem less mysterious. But it could also expose unexpected subclasses within a population that astronomers once thought they understood.

For now, the most dramatic interpretation is not supported. There is no evidence that the 27 newly discovered sources are alien messages, beacons or technology.

What they demonstrate instead may be more important to astronomy: even inside the Milky Way, among the remnants of stars that scientists have studied for decades, entire populations can remain hidden simply because humanity was not looking at the sky in quite the right way.