A Silo is a 9-sector object that can fire missiles if your alliance has full control over the Silo, it can fire missiles and can destroy NPC's, it needs 2500 points to secure it for your own alliance and could be lauched By Leaders and Co-Leaders only
Silo's need 2500 capture points and it will usally take a few hours to take full control over the silo, and requires 9 ships for contest to claim al the territory.
Silos are where nukes appear periodically. But to use nukes, you've to secure that silo for that turn. There are 9 silos in each region. Each silo has 9 secure sectors, all of which contribute towards securing it. Several alliances may try to secure same Nuclear Missle Silo at once, whoever reaches target first has nuke for that turn. Several players of the same alliance can send ships to secure quicker. Or it is recommended to just sent all your ships with some T1 (Tier 1 Troops) . Once a silo is secured, that alliance will have 24 hours to use that nuke. Only leader or co-leaders can fire the Nucler Missle. Nucler Missle are generally used to weaken NPC targets alien, scavenger, dark activity, control testing station, downed dropship, hostile crash site). Bigger the better. One nuke hit will reduce a npc target to 40% power. So, 2 nukes will reduce that target to 16% power. And so on. Nukes doesn’t kill any units on player base / op / gather ship. Just reduces health, which won’t regenerate for 4 hrs, stops res production in base. Also, nukes doesn’t do any damage to invaders armored alien bug, plasma strider, flying saucer, swarm toxic bug, elite plasma strider). If your alliance has secured nuke, try finding multiple targets within 3 tile distance of each other for max benefit from one nuke.