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.
Most experts recommend getting as large a bird cage as you can afford. As a guideline, we recommend customer consider African Grey cages that are 36â wide, 24â deep, and 40â high. However this is not possible a minimum cage size for an African Grey cage is 34â wide, 24â deep, and 36â tall. Also important to the African Grey are bird toys and activities. Be sure you select a bird cage that has sufficient room to add many different toys, activities and perches.