those found on Earth, but scientists now know them to be large flows of lava, which erupted well after the Moon was formed. Like Mercury, the Moon still displays many impact craters, the scars of early collisions with asteroidlike objects. Because it has neither atmosphere nor water, there has been no erosion to erase these ΓÇ£birth marks.ΓÇ¥ Yet not all craters date from the MoonΓÇÖs formation; impact craters inside the maria, for example, must be relatively young, since the colliding objects struck after the maria formed.
Another prominent lunar feature can be seen in this image: the mountains, which form rugged highlands extending over the lunar surface. Associated with
