It's tipped with nuclear!

Behold, the bringer of light

I have stood on that very cannon, at the atomic museun in Abq.

What gives the clouds so many tiers like that?

Some info:

The first artillery test was on May 25, 1953 at the Nevada Test Site. Fired as part of Operation Upshot-Knothole and codenamed Shot GRABLE, a 280 mm (11 inch) shell with a gun-type fission warhead was fired 10,000 m (6.2 miles) and detonated 160 m (525 ft) above the ground with an estimated yield of 15 kilotons. This was the only nuclear artillery shell ever actually fired in the US test program. The shell was 1384 mm (4.5 ft) long and weighed 365 kg (805 lb); it was fired from a special artillery piece, nicknamed "Atomic Annie", built by the Artillery Test Unit of Fort Sill, Oklahoma.