The original trilogy largely revolves around a soldier named Commander Shepard, whose mission is to save the galaxy from a race of powerful mechanical beings known as the Reapers and their agents, including the first game’s antagonist Saren Arterius. The first game, released in 2007, sees Shepard investigating Saren, whom Shepard slowly comes to understand is operating under the guidance of Sovereign, a Reaper left behind in the Milky Way 50,000 years before, when the Reapers exterminated all sentient organic life determined to have met or exceeded a threshold of technological advancement in the galaxy as part of a recurrent cycle of genocide for an unknown purpose. Sovereign’s purpose is to trigger the imminent return of the Reaper fleet hibernating in extra-galactic dark space, restarting the process of extermination. The second game takes place two years later, and sees Shepard battling the Collectors, an alien race abducting entire human colonies in a scheme to aid the Reapers’ return to the Milky Way. The final game of Shepard’s trilogy centres on the war being waged against the Reapers. The fourth installment takes place in the Andromeda Galaxy and features a new cast of characters.
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. "From what we know about cloud formation on Titan, we can say that such methane clouds in this area and in this time of year are not physically possible. The convective methane clouds that can develop in this area and during this period of time would contain huge droplets and must be at a very high altitude--much higher than the 6 miles that modeling tells us the new features are located," Dr. Rodriguez explained in the September 24, 2018 JPL Press Release. "We don't know how long the Dagwood-sandwich structure would exist. This structure represents a stable state, but various factors could mean the moon doesn't reach this stable state," Dr. Christophe Sotin said in a May 1, 2014 statement. Dr. Sotin is of the JPL.