(Nanowerk News) What does Earth look like from an alien civilization light years away? A team of researchers from Mauritius and Manchester University have used data from many people to simulate radio leaks from cell towers and predict what an alien civilization might detect from nearby stars, including Barnard’s star, six light years away from Earth.
Ramiro Saide, currently an intern at the SETI Institute’s Hat Creek Radio Observatory and M.Phils. students at the University of Mauritius, produced a model showing the radio power this civilization would receive as the Earth rotated and the towers rose and fell. Saide believes that unless the alien civilization is far more advanced than ours, they will have a hard time detecting the current levels of cell tower radio leaks from Earth.
However, the team suggests that some technical civilizations are likely to have much more sensitive receiving systems than ours, and the detection of our cellular systems will improve substantially as we move to much more powerful broadband systems.
Saide is also pleased with the fact that his simulations show that the Earth mobile radio signature includes major contributions from developing countries, including Africa. According to team leader Professor Mike Garrett (University of Manchester, Jodrell Bank Center for Astrophysics), “the results highlight Africa’s success in bypassing the land development stage and moving directly into the digital age.”
Garrett is pleased with the results. “I have heard many colleagues say that the Earth has become increasingly radio silent in recent years – a claim I have always disputed – although it is true that we have fewer powerful TV and radio transmitters today, the proliferation of mobile communication systems around the world is notable. While each system represents relatively low radio power individually, the integrated spectrum of these billions of devices is enormous.”
Dr. Nalini Heeralall-Issur, Saide’s supervisor in Mauritius, thinks Saide may be right. “Every day we learn more about exoplanet characteristics through space missions like Kepler and TESS, with further insights from JWST – I believe that it is possible that advanced civilizations are out there, and some may be capable of observing man-made radio leaks originating from Earth. from planet Earth.”
The team is eager to expand their research to include other contributors to Earth’s radio leak signature. The next step will be to incorporate powerful civil and military radars, new digital broadcast systems, Wi-Fi networks, individual cellular handsets, and a collection of satellite constellations now launching into low Earth orbit, such as Elon Musk’s Starlink system.
According to Garrett, “Current estimates suggest that we will have well over a hundred thousand satellites in low Earth orbit and beyond before the end of this decade. Earth is already very bright in this part of the radio spectrum; if trends continue, we could be easily detected by any advanced civilization with the right technology.”
“This work is an outstanding example of how detailed analysis of the properties of human technology (the “anthropogenic technosphere”) can be leveraged to develop exciting new strategies for detecting extraterrestrial technology,” said Telescope Array Project Scientist Allen Dr. Wael Farah “We look forward to using the unique instrumentation capabilities and scheduling flexibility of the Allen Telescope Array, paired with our growing knowledge of nearby exoplanet systems, to undertake new searches based on this strategy.”
Paper accepted by MNRAS (“Simulation of Earth radio leaks from mobile towers as seen from selected nearby star systems”)
The paper too available on arXiv.