Explanation:
Shaped like a target ring bull's-eye, the
Mare Orientale
is one of the most striking large scale lunar features.
Located on the
Moon's
extreme western edge, it is unfortunately difficult to see
from an earthbound perspective.
Still, this mosaic
of the multi-ring
impact basin, the youngest of the
large lunar basins shows off intriguing details
(full
resolution mosaic), based on
Wide Angle Camera images from the Lunar Reconnaissance Orbiter.
Only partially flooded by lava the Mare Orientale
is over 3 billion years old, about 600 miles (950 kilometers)
across and was formed by the impact of an asteroid sized object.
The collision caused ripples in the
lunar crust resulting in the concentric circular features.
Though it may
seem a little ironic to denizens of the space age
who recognize the Moon as a dry and airless world,
a dark, smooth lunar region is called
a mare
(plural maria), latin for sea,
because astronomers once thought
such regions might actually be seas.
