Galaxies are densely clustered near the supermassive black hole at the center of our galaxy – and they may contain a pulsating beacon used by alien civilizations to announce important events.
That’s the general theory behind a new project by scientists with the SETI Institute, a nonprofit dedicated to understanding life in space, Cornell University and the $100 million Breakthrough Listen initiative.
The SETI Institute is a non-profit organization dedicated to understanding life in space.
Unlike SETI’s previous efforts, which focused on continuous narrowband radio signals, the new effort will focus on broadband pulsed radio signals.
These pulsed “beacons,” which the researchers liken to “radar” pings, may be a more likely form of advanced alien communication, thanks to the energy saved between pulses.
The study’s lead author, Akshay Suresh, told DailyMail.com that the galaxy’s core is “ideally placed” for galaxy-wide communications, making it a perfect candidate for intercepting extraterrestrial messages.
Scientists from SETI, Cornell University and the $100 million Breakthrough Listen initiative have set their sights on the core of the Milky Way, where the largest number of stars in our galaxy are crammed together. Above, the Milky Way as captured by a hobbyist’s custom telescope
BLIPPS’ alien beacon search will task the Green Bank Telescope (above) with focusing its search on a cluster of 8 million stars, 27,000 light-years away, at the center of the Milky Way. The Green Bank Telescope is currently the largest fully steerable radio telescope in the world
“By using pulsed signals, a transmitting party can save energy by reducing the time their transmitting antenna has to be on,” the study’s lead author, Akshay Suresh, told Dailymail.com.
“On the other hand,” Suresh said, “a stable beacon, such as an optical laser, must operate continuously.”
According to Suresh, the new project will look for repetitive patterns using a type of software called a “rapid folding algorithm,” which astrophysicists have used in recent years to successfully identify pulsars: highly magnetic and rotating neutron stars.
Like the theoretical alien beacon, pulsars in the galaxy emit a repeating periodic signal as the electromagnetic radiation emitted from their poles rotates along with the rest of the star — pointing cyclically, first toward and then away from Earth.
WHAT IS SETI’S BREAKTHROUGH LISTENING INITIATIVE?
Breakthrough Listen is a privately funded, ten-year research project at the University of California, Berkeley.
It just announced a significant number of new sightings.
They surveyed about 1,300 nearby stars using large antennas in West Virginia and Australia.
For each of these galaxies, they’ve scoured billions of radio channels, looking for a signal of the type that only a radio transmitter can produce.
No extraterrestrial radio emissions were detected.
But those 1,300 stars represent only a minuscule sample of the total planetary population.
Suresh, a graduate student in Cornell University’s astronomy program, said their new SETI project will focus on a series of pulses repeated every 11 to 100 seconds and spaced out over a few kilohertz, “similar to radar transmissions.”
The new project, called Breakthrough Listen Investigation for Periodic Spectral Signals (BLIPSS), will use a ground-based radio telescope in West Virginia called the Green Bank Telescope, supplemented with equipment from Breakthrough Listen.
The Green Bank Telescope is currently the largest fully steerable radio telescope in the world.
However, China has begun construction of a larger rival, called QiTai, which is currently underway in China’s northwestern Xinjiang Uygur Autonomous Region.
In West Virginia, BLIPPS will direct the Green Bank Telescope to direct their search for extraterrestrial beacons to a cluster of 8 million stars, 27,000 light-years away, at the center of the Milky Way.
(A light-year is the distance light travels in a year, which is no less than 9.5 trillion kilometers.)
Suresh said the galaxy’s core is “ideally placed” for galaxy-wide communications, making it a natural focus for the BLIPPS search.
“Of all directions in the sky, we encounter the greatest number of stars when we look at the core of the Milky Way,” Suresh told Dailymail.com.
“Purely statistically,” he said, “we can maximize our chances of finding signs of extraterrestrial technology by looking at the center of our galaxy.”
Over the past decade, astronomers working with data from NASA’s Kepler spacecraft have found that on average one in five stars in our galaxy is home to an Earth-sized planet that could potentially be habitable.
Suresh said that, from a game-theoretic perspective, intelligent species like ours would likely try to use the galactic core as a staging area to deliver “intentional “we’re here” type beacons, among other reasons for interstellar mass communication.
“You can imagine aliens using such light-speed transmissions to communicate important events,” he said, “such as preparations for interstellar migration before the explosive death of a massive star.”
Suresh and his co-authors unpacked the project’s preliminary proof of concept results in a paper published in the Astronomical Magazine late last month.
“Our study sheds light on the remarkable energy efficiency of a train of pulses as a means of long-distance interstellar communication,” said SETI Institute Astronomer Dr. Vishal Gajjar, Suresh’s advisor and co-author of the project.
In fact, the kind of ‘radar’ ping, pulsed signal that BLIPSS looks for is so efficient that the repetitive signal covers a frequency range less than a tenth the width of an average FM radio station.
“This study marks the first-ever comprehensive attempt to conduct in-depth searches for these signals,” said Dr. Gaijar.