The Alien Crash Site Biome is a new biome introduced in the 1.5 update. In this biome, you will come across a meteorite crashed into the ground. This meteorite is made up of Space Rock and several blocks of Space Goo (very important for crafting laser weapons). To defend these blocks, aliens spawn. Aliens are very strong, and tough to kill with basic weapons. It is best to take on this biome as a team if you plan on getting any space goo.
Biomes of this type will start appearing randomly after a distance of 300.
1.5 Update Gallery
Thanks to our friends over at DigitalDNA Studios, they have uploaded screenshots and video demonstrations of concepts you will be seeing once the update comes out and to prove its a work in progress.