Assignment:1. Compare the atmosphere of the Jovian planets. In what aspects are the similar and different?The Jovian or outer planets includes Jupiter, Saturn, Uranus and Neptune. The atmosphere of the four was characterized by colorful, turbulent, cloudy atmospheres and do not have a solid surface on which one could land. Their atmospheres are mainlyhydrogenand helium, with traces of other gases giving them their rich colors. The atmospheric structures of the four Jovian planets are all quite similar. The primary difference is that theatmospheres get progressively coolerwith increasing distance from the Sun.2. Name some Jovian satellites with spectacular characteristics.*Callisto, the outermost Galilean satellite, is larger than the planet Mercury. It also has the lowest reflectivity, or albedo, of the four, suggesting that its surface may be composed of some rather dark, colorless rock. Callisto takes just over two weeks to orbit once around Jupiter.* Ganymede, which requires only seven days for one orbit, is the largest satellite in the Jovian system, being only slightly smaller than the planet Mars. Its albedo is much higher than that of Callisto, or of the rocky planets such as Mercury, Mars, or the Moon. In 1971 astronomers first measured the infrared spectrum of reflected sunlight from Ganymede and found the characteristic absorptions of water ice, indicating that this satellite is partially covered with highly reflective snow or ice.* Europa, which is slightly smaller than the Moon, circles Jupiter in half the time required by Ganymede. Its surface reflects about sixty percent of the incident sunlight, and the infrared spectrum shows prominent absorptions due to water ice; Europa appears to be almost entirely covered with ice. However, its color in the visible and ultraviolet part of the spectrum is not that of ice, so some other material must also be present.* Io, innermost of the Galilean satellites, is the same size as our Moon. It orbits the planet in 42 hours, half the period of Europa. Like Europa, it has a very high reflectivity, but, unlike Europa, it has no spectral absorptions indicative of water ice. Before Voyager, identification of the surface material on Io presented a major problem to planetary astronomersPluto's only know satellite, Charon, is the largest satellite compared to the size of its mother planet. The Earth's moon held that title until Charon was discovered in 1978. Charon's large mass relative to Pluto means that the center of their common orbit about each other lies outside Pluto's surface, another unique characteristic of this Planet.

3. What are the common characteristics of Jovian planets?The Jovian planets do not have solid surfaces. Instead, they are composed primarily of hydrogen and helium, with traces of methane, ammonia, water, and other gases in their atmospheres. They are all primarily big. They are all gaseous. They are the outer planets. 4. How was Neptune discovered? Do you think one can discover still another planet beyond Pluto?The Berlin Observatory astronomer Johann Gottfried Galle used the calculations by Le Verrier to findNeptunewithin just 1 of its predicted location, and just 12 of Adams' predictions. Both astronomers claimed that they were the first todiscoverthe planet, and it led to an international dispute. I think there can still be a planet waiting to be discovered. The possibilities are limitless and the universe is endless. 5. What makes Pluto so unique when it compared to the other outer planets.Aside from being, on average, the farthest planet from the Sun, Pluto and its orbit have several characteristics that make it unique. Its greater distance means its orbital period of 248 years is the longest of all planets. Its orbit has the highest eccentricity, which means that its distance from the Sun varies more than other planets. Its orbit is so far from circular that it can actually be closer to the Sun than Neptune at times.The plane of Pluto's orbit is also tilted the most compared to the rest, taking it further north and south of the Earth's orbital plane than the other planets.Pluto's only know satellite, Charon, is the largest satellite compared to the size of its mother planet. The Earth's moon held that title until Charon was discovered in 1978. Charon's large mass relative to Pluto means that the center of their common orbit about each other lies outside Pluto's surface, another unique characteristic of this Planet.Finally, Pluto itself is unique for its position and physical characteristics. The four inner planets--Mercury, Venus, Earth and Mars--are known as terrestrial planets for their smaller size, solid surface, and similarity to Earth. The next four planets, looking outward from the Sun, are gas giants. They are larger than the terrestrial planets, have a larger number of satellites, and no solid surface. Beyond the gas giants, Pluto breaks the pattern by once again showing characteristics more like a terrestrial planet--small, solid surface, and only one (known) satellite.