9.4 ALIEN MISSIONS
Research: Generally small vehicles, least threat
Harvest: Great concern to governments, usually cattle abduction
Abduction: Abducts humans, causes great alarm
Infiltration: Infiltrates countries and try to make pact with government, big threat as countries that sign pact cease to fund XCOM!
Base: Survey and establish alien base, may contain alien commander, esp. higher levels
Terror: Creates terror sites when lands at city, so get them fast!
Retaliation: Scout / attack XCOM base, greatest threat
Supply: Supply alien bases. Trail them and patrol nearby to find alien base