When viewed through a telescope, the Apollo 12 landing site has fewer craters and a slightly redder color than the Apollo 11 landing site. It was thought that these characteristics indicated that the rocks at the Apollo 12 landing site were both younger and different in chemical composition than the rocks at the Apollo 11 landing site. This material both confirmed the pre-mission expectations and also posed some new questions. The Apollo 11 rocks were a mixture of basalts and breccias. In contrast, the Apollo 12 rocks were almost all basalts, with only two breccias in the returned samples.
Basalts are dark-colored rocks solidified from molten lava.
They are a common type of volcanic rock on Earth and are found in places such as Hawai'i. The basalts at the Apollo 12 site formed 3.1 to 3.3 billion years ago, roughly 500 million years later than the Apollo 11 basalts. Basalt consists primarily of the minerals pyroxene and plagioclase. At the Apollo 12 landing site, several different varieties of basalt were identified from the presence of other minerals such as olivine or ilmenite. Overall, there is much less of the element titanium in the Apollo 12 samples than in the Apollo 11 samples, which explains the more reddish color of this region.