Analysis of Space and Planets - Essay Example

TOPIC ASTRONOMY It was not through telescope that Neptune was discovered, but it was two mathematicians Urbain J. J. Leverrier and John C. Adams who calculated its existence. It was on September 23, 1846 when Neptune was seen near the position Adams and Leverrier had predicted. The planet was named Neptune after the Roman sea god with a symbol of fishing gear. It was in August 1989 when Voyager 2 spacecraft provided the world with the first close-up views of Neptune and most of its moons. The spacecraft further discovered the planet's rings and six of its moons. STRUCTURE OF NEPTUNE This picture of Neptune was taken on August 20, 1989 by Voyager 2. In the center of the image, the Great Dark Spot can be seen. The latitude of the planet Neptune is 22 degrees south and circuits every 18.3 hours. The east and the south of the Great Dark Spot change their appearances constantly in four hours. INTERNAL STRUCTURE Interior of Neptune The internal structure of Neptune can be inferred from the planet's radius, period of rotation, mass, and shape of its gravitational field and the behavior of hydrogen, helium, and water at high pressure. The picture shows a cut-away view of Neptune composed of an outer envelope of molecular hydrogen, helium and methane. Below this region Neptune is composed of a layer rich in water, methane, ammonia, and other elements with high temperatures and pressures. Ice and rock constitutes the core of Neptune. Triton and Neptune This picture gives a nearly true picture of Neptune taken by the Hubble Space Telescope's (HST) Wide Field Planetary Camera (WFPC), with a picture of Triton taken with the HST's Faint Object Camera. Even though, the image of Triton is faint but it clearly shows a bright equatorial region. In the lower left, the south pole is clearly visible. Near the bottom of the image a bright cloud feature can also be seen. It can be seen at 30S and 60S latitude. Another bright cloud can also be seen at 30N latitude in the northern hemisphere. This second image of Neptune was taken after the planet had rotated 180 degrees of longitude, which was about 9 hours later, to show the opposite hemisphere. The dynamic nature of Neptune is clearly visible from the fact that the second smaller dark spot DS2, which had been seen during Voyager-2 journey, had been missing in these pictures. In One feature that is conspicuous by its absence is the storm system known as the Great Dark Spot. HST Observes High Altitude Clouds These three pictures were taken on October 10, October 18 and November 2, 1994 when Neptune was only 4.5 billion kilometers from Earth. The pictures further proved the dynamic nature of the planet as the difference in the temperature between Neptune's Building on Voyager's initial discoveries, Hubble has revealed that Neptune has a remarkably dynamic atmosphere that changes over just a few days. Only in few days, the temperature difference between Neptune's strong internal heat source and its frigid cloud tops were-162 Celcius or -260 Fahrenheit which might be the causes that trigger instabilities in the atmosphere and result in large-scale weather changes. The high altitude methane ice-crystals can be seen in pink. New Dark Spot After the images in June 1994, which showed the disappearance of the Great Dark Spot, on November 2 a new spot, appeared near the limb of the planet. The new spot has high altitude clouds along its edge, resultant of gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a porthole to a cloud deck lower in the atmosphere. Cirrus-like Clouds Bands of sunlit cirrus-like clouds can be seen in this image of Neptune's northern hemisphere. 35 miles mellow, shadows are cast on the blue cloud deck. The width of the white streaky clouds ranges from 48 to 160 kilometers (30 to 100 miles) and extend over thousands of miles. True-color Image The picture taken by Voyager 2 has been edited by computers so that both the clouds' structure in the dark regions near the pole and the bright clouds east of the Great Dark Spot can be seen. Both the small trails of clouds trending east to west and large-scale structure east of the Great Dark Spot suggest that waves are present in the atmosphere and play a large role in the type of clouds that are visible. Great Dark Spot The dark and the light blue regions on the Great Dark Spot are filled with feathery white clouds. The counterclockwise rotation of the storm system is clearly visible from the pinwheel shape of both the dark boundary and the white cirrus. The white clouds, possibly waves, have a short life and Periodic small scale patterns in the white cloud, possibly waves, are short lived and do not continue from one Neptunian rotation to the next. Change in the Great Dark Spot The bright cirrus-like clouds of Neptune change swiftly, often appearing and scattering over several to tens of hours. The cloud evolution in the region around the Great Dark Spot was captured at an effective resolution of about 100 kilometers (62 miles) per pixel during the time span of two rotations of Neptune. The unpredictably swift transformation which occurs over the 18 hours separating each panel illustrates that in this region Neptune's weather is perhaps as changing and variable as that of the Earth. However, the scale is enormous by our standards. High Resolution Crescent Image of Neptune This high resolution crescent image of Neptune was taken by the Voyager 2 spacecraft on August 31, 1989. On the limb of the planet a circular storm pattern can be seen. Parting Look A beautiful dual-crescent view of Neptune and Triton can be seen in this image on August 31, 1989, as a parting tribute of the Voyager mission. The Small Dark Spot In the south of the Great Dark Spot, the Small Dark Spot can be seen which is a small spot and is thought to be a storm in Neptune's atmosphere. Neptune Rings These two 591-second exposures of the rings of Neptune were taken by Voyager 2 on August 26, 1989 from a distance of 280,000 kilometers (174,000 miles). The region image gives a clear view of the two main rings which appear to be complete and continuous. The image also shows the presence of a faint ring at about 42,000 kilometers (25,000 miles) from the center of Neptune, and the faint band which extends smoothly from the 53,000 kilometer (33,000 miles) ring to roughly halfway between the two bright rings. The brilliant glare in the center is because of over-exposure of the crescent of Neptune. Several bright stars are visible in the background. Twisted Rings This portion of one of Neptune's rings appears to be twisted. It is believed by the scientists that it looks this way because the original material in the rings was in clomps that formed streaks as the material rotated Neptune. The movement of the spacecraft also added to the twisted appearance by causing a minor smearing in the picture. COMPARISON BETWEEN NEPTUNE AND EARTH Neptune Earth Position from the Sun 8 (usually) 3 Diameter 30,800 miles (49,500 km) 7,926 miles (12,753 km) Moons 8 1 Rings 4 0 Average Distance from Sun 2,799,000,000 miles (4,504,000,000 km) 93,000,000 miles (149,000,000 km) Your Weight on the Planet Multiply your weight by 1.2 Multiply your weight by 1.0 Length of One Year 165 Earth years 1 Earth year Length of One Day 17 hours and 6 minutes 24 hours What's in the Atmosphere Hydrogen, helium, methane Nitrogen, oxygen Temperature -350F (-210C) -128F to 136F (-89C to 58C) RINGS OF NEPTUNE 1989N3R Distance*: 41,900 km Width: 15 km Albedo: Low 1989N2R Distance*: 53,200 km Width: 15 km Albedo:Low 1989N4R Distance*: 53,200 km Width: 5,800 km Albedo: Low 1989N1R Distance*: 62,930 km Width: < 50 km Albedo: Low *The distance is measured from the center of Neptune to the start of its ring. NEPTUNE MOONS Naiad #: III Radius (km): 29 Mass (kg): Distance (km): 48,000 Discoverer: Voyager 2 Date: 1989 Thalassa #: IV Radius (km): 40 Mass (kg): Distance (km): 50,000 Discoverer: Voyager 2 Date:1989 Despina #: V Radius (km): 74 Mass (kg): Distance (km): 52,500 Discoverer: Voyager 2 Date: 1989 Galatea #: VI Radius (km): 79 Mass (kg): Distance (km): 62,000 Discoverer: Voyager 2 Date: 1989 Larissa #: VII Radius (km): 104x89 Mass (kg): Distance (km): 73,600 Discoverer: Voyager 2 Date: 1989 Proteus #: VIII Radius (km): 200 Mass (kg): Distance (km): 117,600 Discoverer: Voyager 2 Date: 1989 Triton #: I Radius (km): 1,350 Mass (kg): 2.14 + 22 Distance (km): 354,800 Discoverer: W. Lassell Date: 1846 Nereid #: II Radius (km): 170 Mass (kg): Distance (km): 5,513,400 Discoverer: G. Kuiper Date: 1949 Reference: Anonymous. Astronomy Online 2009. The Solar System. 8 Mar. 2009 Read More