I'D LOVE TO ELABORATE because this is one of my favorite astronomy stories.
Okay. So in the field of Radio Astronomy, there's this phenomenon called a "fast radio burst", a very short, strong radio pulse picked up by a radio telescope. They're still poorly understood, and are considered very exciting to radio astronomers because of how rare they are.
In the 2010's, astronomers working at Australia's Parkes Radio Observatory identified a number of radio signals picked up by the telescope that appeared to resemble fast radio bursts, which they called Perytons.
However, they quickly realized that the signals had to be terrestrial in origin due to the strength of the signal.... as well as the fact that they always occurred during weekdays, around the same time.
The signals tended to be clustered around midday... hmm...
Further evidence that the signals were man-made... this trend also followed daylight savings!!!
(Unless aliens also follow Australian daylight savings conventions, which is highly unlikely...)
They were unable to recreate the signal, until they tried opening the microwave door before it beeped. Turns out the microwave was letting out a tiny amount of radio emissions when the door opened, which the nearby telescope was sensitive enough to detect.
The Peryton signals had been popping up in the data for over a decade, presumably because astronomers taking their lunch breaks had been opening the break room microwave prematurely for the same reason cited by OP.
I imagine they must have a big sign reading "LET THE MICROWAVE FINISH BEFORE OPENING" hanging in the break room now.
TLDR: If you work in radio astronomy, let the microwave beep before opening it and removing your lunch.