Mars: Hellas Planitia. The largest visible impact crater in the Solar System is Hellas Planitia on Mars, a giant depression with a floor over seven kilometres (4.3 miles) below the Martian surface.
Dimensions. The recommended size for one parakeet is 25 inches tall and 25 inches deep. To house two birds comfortably, you should double that cage size to make it at least 50 inches tall and 50 inches deep.If you can afford it and have enough space, opt for a bigger cage.all cages work best for parakeets. This type of bird really likes to fly around and hop from place to place. If you can, choose a cage that exceeds the height recommendation of 50 inches.
Subfamily: Arinae. Identification: The Monk parakeet is a parrot of average size, reaching a length of about 29cm (11 1/2 inches) from head to tip of tail. Both females and males have a bright green body, gray forehead, cheeks and breast, blue-black flight feathers, gray legs and a rosy, pale orange or yellow beak.enefits: Monk parakeets positively play on the psychology of the inhabitants of the areas they have invaded, since most of these places are cities which contain very little wildlife. These gregarious, bright birds add a natural element to city streets, which often support little plant and animal life.