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Earth's Moon Reveals An Ancient Secret. Many astronomers think that during an ancient era, termed the Late Heavy Bombardment, our young Moon was violently battered by a marauding multitude of invading asteroids that crashed onto its newly formed surface. This attack of pelting objects from space occurred about 4 billion years ago, and the shower of crashing asteroids excavated impact craters, and also slashed open deep fissures, in the lunar crust. This sustained shower of merciless impacts increased lunar porosity, and opened up an intertwining network of large seams under the Moon's surface. The existence of such powerful roaring winds kicking up violent and powerful dust storms suggests that the underlying sand can be set in motion, too, and that the giant dunes covering Titan's equatorial regions are still active and continually changing. Makemake, like Pluto, shows a red hue in the visible part of the electromagnetic spectrum. The near-infrared spectrum is marked by the existence of the broad methane absorption bands--and methane has also been observed on Pluto. Spectral analysis of Makemake's surface shows that its methane must be present in the form of large grains that are at least one centimeter in size. In addition to methane, there appears to be large quantities of ethane and tholins as well as smaller quantities of ethylene, acetylene, and high-mass alkanes (like propane)--most likely formed as a result of the photolysis of methane by solar radiation. The tholins are thought to be the source of the red color of the visible spectrum. Even though there is some evidence for the existence of nitrogen ice on Makemake's frozen surface, at least combined with other ices, it is probably not close to the same abundance of nitrogen seen on Pluto and on Triton. Triton is a large moon of the planet Neptune that sports a retrograde orbit indicating that it is a captured object. Many astronomers think that Triton is a wandering refugee from the Kuiper Belt that was captured by the gravity of its large, gaseous planet. It is possible that eventually the doomed Triton will plunge into the immense, deep blue world that it has circled for so long as an adopted member of its family. Nitrogen accounts for more than 98 percent of the crust of both Pluto and Triton. The relative lack of nitrogen ice on Makemake hints that its supply of nitrogen has somehow been depleted over the age of our Solar System.