The origins of this mystery dates back to early 2000's. The small SETI (Search for Extraterrestrial Intelligence) office in the Hat Creek Observatory, located in the Cascade Mountains was filled with the noise of computers beeping and buzzing.
They had just detected an alien transmission and were repeatedly receiving the same transmission for about an hour now. Language Experts were flown in early in the morning at 2:35 AM to assess the transmission and find out what they meant and who were transmitting them.
After a day of analysing them, the scientists narrowed down the origin of these signals to a star "GJ 3059" that's about 70 Light-years from the Earth.
A week later, the Language Experts produced the final draft of their transcript:
"Beware! A large group of Dangerous Intelligent Machines are coming towards your planet. They will destroy all the life on your planet to make it suitable for an alien species. The only way to protect your planet is to create another planet near-by with life and Radio Transmission and stop radio transmission and artificial lights on your planet. There is roughly 170 Earth-years before these machines reach you. You must go radio-silent within 140 years to hide your exact location."
The major leaders of the most powerful nations had a confidencial meeting and decided to maintain this as a Top Secret and signed an agreement to dedicate significant resources in creating a decoy planet.
Major corporations were funded to develop technologies required to colonise Mars. Venus was supposed to be the plan-B. A team of PR experts were appointed to suppress public opinions against funding space travel.
On Day-Zero, the world-leaders announced that there have been major solar flares and all of the communication satellites and major radio communication devices have been destroyed. And more solar flares are expected in the near future. So, all communication will be switched to Optic-fibers and low-range transmissions only for a few years. Almost all artificial lightings and electric grids have also been destroyed. Electricity will only be supplied during the day and do not step out of your homes, after sunset.