there is no way to know, for sure, about what is happening, simply due to a lack of records for comparison.

tl;dr: we don't know exactly why, but there's more this year, they're bigger, and more are reported (that probably due to more cameras and ease of reporting). Probably just a bumper crop this year.

No military operations to see here, just rocks

See starship troopers. Aliens are target practicing for a much larger asteroid.