If the notion of capturing radio signals from **space** brings to mind Jodie Foster in *Contact*, eagerly awaiting extraterrestrial schematics from Vega, you’re not entirely mistaken—but the truth is significantly less cinematic and far more rooted in science. Although it may not possess the excitement of a major film, the genuine endeavor of interpreting radio signals from space is anything but uninteresting.
Radio telescopes, including the now-retired **Arecibo Observatory** in Puerto Rico and various others worldwide, are not primarily built to find intentional communications from aliens. That would be akin to claiming your eyes mainly exist to spot grizzly bears—it isn’t inaccurate, but it certainly doesn’t tell the full story. Rather, these telescopes function as cosmic monitors, “observing” the **radio sky**—a broad array of emissions from the universe detectable from our planet. This encompasses phenomena such as **pulsars**, **solar flares**, and **cosmic microwave background radiation**, along with signals closer to Earth from satellites and space probes.
In 2024, the radio telescopes on Earth detected an assortment of intriguing signals. While it is unlikely any of them are from extraterrestrial beings, each one is fascinating and provides insights into the enigmas of the universe. Below are five of the most compelling radio signals identified this year:
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### 1. An Enigmatic Slow Pulse
The **Australian Square Kilometre Array Pathfinder (ASKAP)** radio telescope reported a strange signal, referred to as **ASKAP J193505.1+214841.0**, which was initially detected before 2024 but detailed in a June release. This signal recurs every 53.8 minutes—much too lethargic to be a pulsar, which typically originates from rapidly spinning neutron stars. Pulsars emit signals at high velocities, resembling the spins of a drill bit, rendering this slow, consistent pulse a perplexing oddity. Researchers are still working to decipher its source, but as with many discoveries, what appears “impossible” at first can often lead to groundbreaking revelations.
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### 2. A Strong, Ancient Burst
Fast radio bursts (FRBs) are brief, intense surges of radio waves that temporarily dominate the radio spectrum. One such burst, **FRB 20220610A**, traversed an astounding 8 billion years through space before arriving at Earth. Given that the universe itself is estimated to be 13.8 billion years old, this makes FRB 20220610A one of the most remote—and powerful—radio bursts ever recorded.
Observed by ASKAP with support from the **Hubble Space Telescope**, this signal is believed to have come from an area in space where up to seven galaxies might be merging. According to NASA, this finding offers crucial insights into the extreme conditions that generate such intense bursts.
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### 3. Radio Interference from Starlink Satellites
Astronomers have long expressed worries about the disruption caused by SpaceX’s **Starlink satellites**, which now exceed 6,000 in orbit. These satellites, intended to offer internet connectivity, produce signals that generate unwanted interference for radio telescopes. Nevertheless, in 2024, researchers at the Netherlands’ **LOFAR observatory** discovered that the new **V2-mini Starlink satellites** emit up to 32 times more interference than prior versions.
This interference hampers the examination of low-frequency signals essential for studying exoplanets, black holes, and ancient cosmic occurrences. While designated radio quiet zones are established to shield observatories from interference, no regulations currently control satellite emissions. With thousands of satellites already in orbit and more on the way, this unregulated frontier presents a growing challenge for astronomers. Thanks, Elon Musk!
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### 4. Another FRB Reveals New Insights
Another fast radio burst is aiding scientists in unraveling the origins of these enigmatic phenomena. This signal, associated with a **magnetar**—a neutron star with a powerful magnetic field—was first identified in 2020 but examined in greater detail in 2024. The magnetar, identified as **SGR 1935+2154**, emitted a signal that researchers at Caltech’s **Deep Synoptic Array-110 (DSA-110)** have traced back to massive, star-forming galaxies abundant in metals.
This discovery refines the types of environments in which FRBs are likely to be generated, bringing scientists closer to comprehending the conditions that give rise to these extreme cosmic occurrences.
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### 5. The Expanding Radio Cosmos
Radio telescopes continue to discover new phenomena that challenge our comprehension of the universe. From enigmatic signals like ASKAP J193505.1+214841.0 to ancient bursts such as FRB 20220610A, each finding contributes a piece to the puzzle of the cosmos. While none of these signals are probably from alien civilizations, they serve as a reminder of the vast and ever-changing universe we inhabit—and the remarkable instruments we have to investigate it.