In science, uncertainties are often more exciting than confirmations, and those that have made some puzzled astronomers scratch their heads in recent days have enough to feed an embryo of a Hollywood scenario: in the Milky Way, a mysterious object sends towards the earth a signal every 18.18 minutes.
Like explains it New Atlas, the phenomenon was discovered by a team of scientists thanks to the Murchison Widefield Array (MWA), a giant low-frequency radio telescope based in Australia, tasked with scanning the skies to better understand its most primitive past.
Like in a movie, while mechanically looking for passing objects in the Milky Way, a student named Tyrone O’Doherty came across a powerful signal, which seemed to be unable to come from any object already known to science.
By digging through the massive data previously captured by the radio telescope for the same area, the team realized that the signal captured was not a unique phenomenon. Quite the contrary: when the thing emitting it is active, it repeats itself, with the regularity of a distant Swiss cuckoo clock, every 18.18 minutes.
A Swiss cuckoo, more distant
“This object appeared and disappeared in a few hours during our observations”, described Natasha Hurley-Walker, leader of the discovery team. “It was completely unexpected. It was a little scary for an astronomer, because no known celestial object behaves like this. And it’s pretty close to us – about 4,000 light years away. It is in our galactic pre-square.
Stranger still, the object in question “woke up” in January 2018, then stopped sending a signal the following month, before resuming sending every 18.18 minutes in March. However, nothing appeared in the data for the five years preceding this activity, and the thing has since again found silence.
Scientists are therefore trying to understand what it is all about. An alien civilization? Unlikely, they explain: the characteristics of the signal sent seem rather to be those of a natural object.
Because it appears to be rotating and provided with a magnetic field, it could be a pulsar or one magnetar, but with strange and previously unknown properties – it would spin much slower than science has already observed.
“The fact is, when you do all the math, you know that these objects should only have enough energy to produce this type of radio signal every 20 minutes.”, says Hurley-Walker, whose team published his findings in Nature, and explained them in a video visible below.
Natasha Hurley-Walker speculate that it is a “ultra-long period magnetar”, a long-rotating magnetar, something that existed in theory but had never before been observed in nature. This type of star could also be responsible fast radio bursts, another mystery of nature that science seeks to understand.
Whatever its nature, it will be necessary for the widget to wake up again, or for other corners of the universe to reveal it, to allow more observation and understanding.
Unless, to contradict the scientists and dream like in an old american movie, these are not the first signs of intelligent extra-terrestrial life, hidden nearby and ready to come and greet us in person.