Explain Defensive Structures?

Will defensive structures also mean long range artillery installations?
I would love to see some big bertha action in PA.

Already answered, check the list of confirmed features:

viewtopic.php?f=61&t=34022

To be more specific, there is a link after:

Artillery warfare:
http://www.pcgamer.com/previews/planeta ... ith-moons/

Contains the quote:
"So when he thinks about units that have to be in Planetary Annihilation, some kind of super-heavy artillery piece is near the top of the list."

One of the coders of TA loved the Big Bertha. His name is Jon Mavor and he goes by the nickname of neutrino.

also this:

http://supcom.wikia.com/wiki/UEF_Experimental_Artillery

You're implying I wasn't implying that, but I was. But thanks for pointing it out. (I felt like it'd be like explaining a joke.)