The Ark Class ship formed part of the three-fold survival plan of the wealthy and powerful of the Petroleum Age. The other two legs of the plan were the arcologies, and space habitats.
A slight rustle of the wind... and it stands before you. A Unicorn, whiter and more beautiful than you ever imagined it. It has deep wonderful eyes, and you can't help but admire this creature. It came to have a look at you, and now it freely goes. You have not the heart to stop it, and it silently vanishes between the trees.
Note: unless specially needed, this encounter should never happen again.