LibriumArcana.Games

This is a (piss poor) attempt to work a number off that first shot that the Macross fired in the series. I took a few shortcuts and used a triangle, circle, and asteroid calculator.

Some Numbers:
~1600m to the edge of the island
~90m to lower edge of the gun
100m2 for gun blast area
6372km mean radius for Earth

Plugging 1600m, 90m, and 90* into the triangle calculator leads to a 3 degree declination which I used for the central angle in the circle caculator along with the radius of Earth.

Plugging this and 6372km into the circle calculator gave me a chord length of 333.6km and a volume of ~3.330E+9.

Using Mike Wong's asteroid calculator, that yields an asteroid about 1853m in diameter and vapourization energies of 24.5 gigatons for hard granite and 2 gigatons for ice.

This is a good baseline. Increasing the height of the lower edge of the gun will lead to a larger declination. From what I remember, the blast went through the mountian and immediately into the ocean, so the 1600m figure should be correct. The gun did vapourize (Blew away? The animation always reminded me of something that was being scoured away. A cosmic sand blaster) several large ships in this blast as well, so the figure is higher.

Going by the official RPG stats:
The Macross Heavy Particle Cannon (The Reflex Cannon)
Primary Purpose: Heavy Assault
Secondary Purpose: Anti-Warship
Range: 60,000 miles(96,000km) in atmosphere. Double in space
Size of blast: 2 miles(3.2km) wide
Damage: Destroys EVERYTHING. If used against a planet will leave a crater that ranges in size from 20-120 miles long and 300-1800 feet deep.
Rate of Fire: Once per 5 minutes
Payload: Effectively unlimited(If the ship has power, it can fire)

I'd give the exact stats for the damage done against a planet, but the rpg lists them in the game system stats(Paladium) so unless you can convert MDC to a form of actual damage they'd be rather meaningless. But if you want 'em, here they are:
3D6x1,000,000 MD
so 3-18million MD.