Alien cloud forms on the first day of spring

These hefty clouds caught my eye this afternoon. They seem to have more substance than clouds typically do. I applied the 'dramatic tone' feature from my camera to enhance the effect.

Then I thought, what if they weren't clouds at all, but alien spacecraft disguised as low-lying clouds, hovering overhead, taking photos of earthlings driving about, then posting the photos on their version of blipfoto?