Before anyone points and laughs too hard at the Indian Army I'll recount the following.
Some 20 years ago I was the EngO at Byron Heights in West Falkland. At about 4 one morning I was woken by the CO because of a problem with the radar. That wasn't unusual (ah, the good old Plessey AR-3D) but today's problem was a bit odd: there seemed to be an aircraft loitering over in the eastern sky and it wasn't showing up. The CO was very worried by this apparent aircraft and was considering getting on the secure phone to MPA to ask the QRA to go and have a look, but also wanted to know why this bright light wasn't on radar.
It all sounded odd (an aircraft to the East would be in the opposite direction to Argentina) and almost immediately I had a suspicion what this was. As soon as we were outside the block of bolted-together shipping containers that formed our accommodation my suspicion was confirmed.
"Sir, that's the planet Venus."
"Are you sure?"
"Yes. I'm a bit of a nerd when it comes to star-gazing and right now Venus is very bright in the pre-dawn sky."
"But it's not showing up on radar" (At this point my already low estimation of the CO's technical understanding of our kit plummeted even further.)
"Well, no. Our range against an aircraft is a couple of hundred miles and although Venus is a lot bigger it's also tens of millions of miles away and that more than makes up for it." (I didn't even touch on the topic of how the round-trip time for the echo was several minutes and the radar was designed to expect a return within a couple of milliseconds.)
"So... no point alerting the QRA then?"
"No sir, it's a bit above the F3's ceiling." (I heroically resisted the temptation to say "Well, if you feel unsure..." because the cost of fuel and the risk of an unnecessary sortie outweighed the prospective schadenfreude of the CO becoming known for having launched the QRA against Venus.)