A MYSTERIOUS interstellar signal once thought to be a sign from aliens has left scientists with more questions than answers.
The space laser has stumped researchers for nearly five decades since its discovery.
Astronomer Jerry Ehman was so shocked when he found the anomaly in August 1977 that he scrawled the word “Wow!” on the printout – and the name stuck.
While researchers continue to puzzle over the source of the signal, one team believes they may have identified the mechanism behind it.
Research submitted to arXiv on August 16 presents a new hypothesis: The “Wow!” signal is the result of a hydrogen cloud and blast of radiation colliding.
A team headed by Abel Méndez of the University of Puerto Rico at Arecibo strove to connect the dots between the signal and similar emissions detected over the past few years.
“Our latest observations, made between February and May 2020, have revealed similar narrowband signals near the hydrogen line, though less intense than the original Wow! signal,” Méndez wrote.
Although the original signal lasted just 72 seconds, it was undeniably powerful.
The burst of radio waves measured near 1420 MHz, which is the frequency generated by a change in the energy state of hydrogen atoms.
Scientists have speculated the “Wow!” signal might be used by aliens to indicate their presence.
But the signal didn’t move, ruling out the possibility of a satellite, and didn’t repeat in the way a deliberate transmission might.
Not to mention, many stellar objects emit radio waves with a wavelength of 1420 Mhz.
It’s unlikely aliens are using such a mechanism to signal their presence. So what could it be?
The researchers combed through archival data, looking for brief emissions of narrowband radio waves similar in frequency to the “Wow!” signal.
They narrowed their findings down to four readings in the direction of a red dwarf called Teegarden’s Star.
While the frequencies were not an exact match, they were similar enough to glean information about the “Wow!” signal’s origin.
The signals near Teegarden’s Star are associated with clouds of cold hydrogen that float between stars.
A flash of radiation traveling through a cloud of chilled hydrogen could be enough to generate a microwave laser.
The intense concentration of light at the hydrogen line could appear like the “Wow!” signal from a distance, the scientists hypothesized.
An alternate explanation could be a magnetar. This scary word describes a powerful stellar object – a neutron star with a strong magnetic field.
Magnetars are known for their powerful bursts of X-rays and gamma rays, which are thought to be caused by the rearrangement of their magnetic fields.
They have been linked to fast radio bursts, another signal that has long baffled scientists.
A specific type of magnetar called soft gamma repeater, which periodically spits out radiation, could be to blame.
The scientists plan to continue their research, combing through years of data to unlock the secrets of the universe.
What is a magnetar?
A magnetar is a type of neutron star with an extremely strong magnetic field.
They are a subtype of neutron stars, which are the remnants of massive stars that have exploded in supernovae.
The magnetic field of a magnetar is about 1,000 times stronger than that of an ordinary neutron star, and it can be up to a trillion times stronger than Earth’s magnetic field.
Magnetar bursts can release as much energy in a few seconds as the Sun does in over 1,000 years.
The magnetic forces can also cause the star’s outer layers to be ejected, resulting in additional X-ray emissions.