The NATO first confirmed prove of alien life forms years before aliens would ever set foot on planet earth. The aliens, being not quite human, were unanimous in their decision to scan and analyze earth from every angle imaginable before they began exploring earth with their own eyes.
Safety and the preservation of alien life were of utmost importance for them.
After years of research the aliens concluded unanimously that planet earth did not possess any weapon that could burn through their hard and thick skin or even damage their robust and elaborate technology. The human cultures however were deemed too primitive to allow sensible communication to the point of bonding.
Billions of aliens swarmed planet earth in the same hour, in the same minute. They experienced great joy in seeing Earth's beautiful nature. The human customs and technology were perceived as cute, adorable even. Inevitably, militaries all around the world misunderstood the appearance of unannounced aliens in their countries as declarations of war and many leaders wanted to abduct said aliens to try and find a way to weaponise them. The aliens laughed whole-heartedly as humans tried binding their massive limbs or shooting their impenetrable skin. They showed compassion for the army's frustration to a point, but not without displaying a deep understanding that humans were without a doubt, a highly inferior and primitive life form.
Some humans approached the aliens with friendly intentions and curiosity. Enticed by the simple ways and cute small faces of the humans, most aliens took the time to try and explain some of the things that the humans had never heard about. It was an almost fruitful exchange of information even though the aliens had no intention to grant any knowledge that might advance the technology of this immature and volatile species to a point where they might hurt themselves even more than they already did. Even the most empathic alien did not let itself get emotionally attached to a human, knowing their self-destructive tendencies.
There was a reason the aliens had found humans' home planet before the humans had found the aliens' home planet.
Despite feeling great marvel and excitement for earth and its inhabitants, the aliens kept to themselves to form emotional connections. They adopted a few homeless people from war-torn country before they continued their journey to explore the universe. Humans would forever remember the events as they were told to them: Aliens had tried to invade their homes but with the help of military action, missiles and bombs, earth had successfully defended its place in the universe.