Clearly, the wave is from movement and noise generated by a large (multi-mile long) subterranean hard drive or processor or machine spinning to life after having been given the "wake on LAN" (or some other SSH/RDP-like) signal from Oumuamua [1] - who just got into wifi range earlier this year. The signal is just too clean for it to be natural; it must be artificially generated. So, its either aliens returning, or some Earthly code recently got deployed for Earth 2.0. (Oh, did you think we were living in Earth 1.0...Hmmm, interesting. Do you also think that's air that you're breathing?) ;-)