What do the Galapagos and the moon have in common?

Well, everywhere in the Galapagos Islands we can find volcanoes that have been formed by successive lava flows. This volcanic feature can be seen in various types, sizes and ages throughout the archipelago. There are two types of lava flows in the Galapagos: "aa" and "pahoehoe". In both cases, they are formed by a fluid basaltic magma that emerges from a magma chamber. With a temperature of at least 2,000øF, it flows downhill like a fiery river. As it flows, it cools and becomes more viscous. Near its source, the lava may flow at many kilometers per hour but it becomes slower until, at its limits, it may crawl along as slow as a snail's pace. Because the surface is in contact with the air, it cools most rapidly, forming a crust. Rubbly surface in the case of the "aa" lava, or smooth and thin-skinned in the case of the "pahoehoe". Now, after all the explanation you may be still thinking, what do the Galapagos and the moon have in common? Well, let me give you another hint. As magma cools, minerals crystallize at different temperatures. The water plays an important role because it affects the temperature at which crystallization occurs and the types of minerals formed during cooling. Olivine (see the picture at left) is a mineral formed at high temperatures and may separate early from the cooling lava. It is found in high concentrations all over the inorganic beach on Floreana Island. The successful landings on the moon, beginning with Apollo 11 in 1969, initiated a new era of mineralogic and petrologic research. Rock samples brought from the moon have been studied in incredible detail. Surprisingly, the lunar mineralogy is much less complex than that of the earth, and among the major lunar minerals found in the lunar rock samples is OLIVINE! Now you know what the Galapagos and the moon have in common!!