Unlike previous Sidewinder iterations with a single-sensor thermal seeker, the AIM-9X has a thermal imaging seeker - it was used to shoot down the much larger balloon last week.
If it was not a drone, and "not a balloon", what could it be?
Assuming this was a drone, the "car-sized", "unmanned", "not a balloon", "not maneuverable" (!?), the operating altitude (40k feet / 13 km), and use of AIM9X (IR/heat seeking) should narrow down the possible drones.
Also, one thing I pondered: why F22 instead of F35 to shoot it down? Maybe a question of availability. But, at least publically the F35 operating ceiling is lower than F22, so I was thinking whether the object was in reality higher than the publically known F35 operating ceiling.
> If it was not a drone, and "not a balloon", what could it be?
It could be an unmanned glider with some solar power.
Several companies make those. Including Google, which was considering them as data relays back around 2016.
The F22 is America's superiority fighter, still beating the F35 in stealth and capability for anti flying things action. The F22 will probably be the default in most intercept circumstances.
> Brig. Gen. Pat Ryder, Pentagon press secretary, told reporters Friday that an F-22 fighter aircraft based at Joint Base Elmendorf-Richardson shot down the object using the same type of missile used to take down the balloon nearly a week ago.[0]
It's considered a "system-guided" missile, not heat-seeking. It's much more advanced than the original heat-seeking concept and integrates additional optical technology in the fuse.
"Shot Down using an Aim9x"
That actually narrows it down a bit. Heat seeking warhead.