Quantum entanglement and wormholes tho. Whether either actually exist outside of government-sponsored science propaganda journals is unknowable to the layperson, but those seem to the be the top two theories in pop culture that would allow for a sudden alien invasion at a convenient time for our globalist overlords.

Now that they've primed us with decades of sci-fi fluff demonstrating how the above might enable Sirius to launch a full-scale assault on Sol, all they really need are fancy lasers (ground, sea and/or space) capable of producing photorealistic holograms in the sky to terrify the sheeple since chinavirus proved how fucking gullible most of us are.

It's been a decade plus since dead musicians returned to 3D life on stage thanks to rather rudimentary laser-CGI, but we now know for a fact that AI can generate photorealistic images from scratch in mere seconds (albeit with too many fingers and teeth). Assuming the level of technology civilians get to see is far inferior to what the military have on hand, it's plausible that the technology already exists to create photorealistic UFO holograms.

My advice? Blow smoke at the UFOs and look for diffraction.