Scientists have broadened their hunt for technologically sophisticated extraterrestrial civilizations by looking for a form of signal that may be created by possibly intelligent aliens that has previously gone unnoticed.
Previously, attempts to discover extraterrestrial technology traces centred on a narrowband radio signal type concentrated in a narrow frequency range or on single anomalous broadcasts. The latest endeavour, scientists said on Wednesday, focuses on a novel signal type that may allow evolved civilizations to communicate over huge interplanetary distances.
The scientists are watching for wideband pulsing signals with repetitive patterns – a sequence of pulses repeated every 11 to 100 seconds and span over a few kilohertz, comparable to pulses used in radar transmission. The search encompasses a frequency range that is about one-tenth the span of a typical FM radio station.
“The signals searched in our work would belong to the category of deliberate ‘we are here’ type beacons from alien worlds,” said Akshay Suresh, a Cornell University graduate student in astronomy and main author of a scholarly article outlining the new endeavour published in the Astronomical Journal.
“Aliens may use such beacons for galaxy-wide communications, for which the Milky Way’s core is ideal.” “One can imagine aliens using such light-speed transmissions to communicate key events, such as preparations for interstellar migration before a massive star explodes,” Suresh said.
The Breakthrough Listen Investigation for Periodic Spectral Signals (BLIPSS) project is a cooperation between Cornell University, the SETI Institute, and Breakthrough Listen, a $100 million programme to seek for sophisticated alien life.
“In the realm of searching for extraterrestrial intelligence, or SETI, we embark on a journey to detect signals from technologically advanced extraterrestrial civilizations,” said Vishal Gajjar of the SETI Institute and the University of California, Berkeley.
“However, the nature of these signals remains unknown, leaving us unsure of their specific characteristics.” As a result, it is critical to investigate a wide range of signals that are unlikely to exist naturally in the cosmic environment,” Gajjar stated.
BLIPSS has focused on a slice of the sky less than one-200th the size of the moon, spanning towards the centre of the Milky Way around 27,000 light years distant, using a ground-based radio telescope in West Virginia. A light year is the distance travelled by light in a year, which is 5.9 trillion miles (9.5 trillion km).
Suresh estimates that this region includes around 8 million stars. If alien life exists, it seems likely that it will inhabit rocky planets circling a star in what is known as the habitable zone, or Goldilocks zone – not too hot or too cold.
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Scientists in different monitoring programmes passively check for extraterrestrial transmissions and do not deliberately broadcast signals announcing our existence on Earth.
“Transmission of ‘we are here’ type beacons, in my opinion, comes with the risk of potentially inviting aliens with unknown intentions to Earth,” Suresh added.
Deliberate broadcasts to prospective aliens from Earth should be considered only if humanity as a whole thinks it safe and suitable, according to Gajjar.
“In my personal opinion, as a relatively young species on the grand cosmic scale, it would be prudent for us to focus on listening and investigating before embarking on deliberate transmissions,” Gajjar added. “It is also important to recognise that sending signals on behalf of the entire Earth raises political and ethical concerns.” At the moment, it would be inappropriate for a single nation or group to make choices for the whole globe.”
In the surveillance operations so far, no aliens have been spotted.
“So far, we haven’t found any conclusive evidence.” “However, it’s worth noting that our investigation has been limited to a relatively small parameter space,” Gajjar said.
