Can a fighter lock any metal in the air?

If a fighter uses a medium-range or extended-range air-to-air missile for locking attack, the missile seeker must be something like radar, so this missile can only lock objects that can reflect electric waves, that is, objects that can be found by radar.

The other is locking by heat source, which is used by most melee bombs.

However, there is a premise that whether it is radar guidance, infrared (heat source) guidance or laser guidance, it is necessary to meet its locking conditions.

The plot in Iron Man is fictional, but it is also possible. Because the radar performance of the F-22 is very good, it can still lock the human-sized metal at close range.

As for birds, they are too small to be locked, but birds can be tracked and locked by radar, even special cyclones [isn't this the patent of old F- 15? (*^__^*)]

Meteorite depends on its size and material. If the main part is metal, it should be locked if it is not too big. If the metal content in its composition is too small, then it must be larger to be locked by radar.