Planets, orbits Saturn

The density estimates in Table 7.1 show a distinction between the structures of the planets, with Mercury, Venus, Earth and Mars all having mean densities consistent with a rocky internal structure. The Earth-like nature of their composition, orbital periods and distance from the Sun enable these to be classified as the terrestrial planets. Jupiter, Saturn and Uranus have very low densities and are simple gas giants, perhaps with a very small rocky core. Neptune and Pluto clearly contain more dense materials, perhaps a mixture of gas, rock and ice. 

The outer planets also tend to have a number of satellites with (at last count) 56 orbiting Saturn, 63 around Jupiter, 27 around Uranus, and 13 around Neptune, compared to the virtual absence of satellites in the inner planets Mercury with 0 Venus, 0 Earth, 1 and Mars 2. 

The many moons of Saturn are readily shown to orbit the planet at commensurable distances, exactly analogous to those of the planets orbiting the sun. Assuming the moon Hyperion to reside at a relative orbital distance of 5/6, which means N = 5, the other major moons, likewise assume integer A-values. 

The giant planets, Jupiter, Saturn, Uranus, and Neptune, occupy the 5th through 8th planetary orbits, eounting outward from the Sun. They seem to form pairs Jupiter and Saturn are similar in size and other properties, and so are Uranus and Neptune (see Appendix 3). All giant planets have deep atmospheres, composed mainly of... 

In the region of the terrestrial planets, there may have been several thousand planetesimals of up to several hundred kilometres in diameter. During about ten million years, these united to form the four planets—Mercury, Venus, Earth and Mars—which are close to the sun. Far outside the orbit of the planet Mars, the heavier planets were formed, in particular Jupiter and Saturn, the huge masses of which attracted all the hydrogen and helium around them. Apart from their cores, these planets have a similar composition to that of the sun. Between the planets Mars and Jupiter, there is a large zone which should really contain another planet. It... 

Jupiter and Uranus are outer planets composed mainly of gases. Jupiter s atmosphere contains reddish-brown clouds of ammonia. Uranus has an atmosphere made up mainly of hydrogen and helium with clouds of water vapor. This combination looks greenish to an outside observer. In addition, Mars has an atmosphere that is 95% carbon dioxide, and Venus has a permanent cloud cover of sulfur dioxide that appears pale yellow to an observer. Mercury has no permanent atmosphere. Saturn has 1 km thick dust and ice rings that orbit the planet. The eight planets in our solar system are diverse, each having different chemical compositions within and surrounding the planets. Out Earth is by far the friendliest planet for human existence. 

Some of the elements of war have found a place in peacetime. The same kind of reaction in uranium that makes an atomic bomb explode can be controlled to make electricity in a nuclear power plant. The Cassini spacecraft now orbiting the planet Saturn runs on plutonium fuel. Plutonium-based fuel was also used to power devices that the Apollo 14 astronauts left on the Moon, such as a seismometer left to detect movements of the Moons crust. The Voyager spacecraft also sent its golden record out to the stars with... 

Figure 8.2 Logarithmic spiral with superimposed mean planetary orbits. The circles in blue define the orbits of inner planets on a larger (self-similarj scale. The divergence angle of 108° causes those planets at angles of 5 x 108° apart to lie on opposite sides of the spiral origin. These pairs are Neptune-Mars, Uranus-Earth, Saturn-Venus and Jupiter-Mercury. The hypothetical antipode of the asteroid belt, a second, unobserved group of unagglomerated fragments, has been swallowed up by the sun...

Planetary-mass bodies probably formed in the Asteroid Belt and were responsible for its dynamical excitation, radial mixing, and mass depletion. The orbits of these bodies became unstable once Jupiter and Saturn formed. These objects and most remaining planetesimals fell into the Sun or were ejected from the Solar System. The Asteroid Belt may have been further depleted when the giant planets passed through a resonance before reaching their current orbits. The Asteroid Belt has lost relatively little mass due to collisional erosion, and most asteroids >100 km in diameter are probably primordial. 

Comet-like materials are presumed to be the budding blocks of Uranus and Neptune (the ice giants) they may have played a role in the formation of Jupiter and Saturn (the gas giants) and they also played some role in transporting outer solar system volatile materials to inner planets (Delsemme, 2000). The inner solar system flux of comets may have been much higher in the past and comets may have played a role in producing the late heavy bombardment on terrestrial planets (Levison et al., 2001). Comets also exist outside the solar system and there is good evidence that they orbit a major fraction of... 

Jupiter, and Saturn. These planets and the sun also perturb the moon s orbit around the Earth— Moon system s center of mass. The use of mathematical series for the orbital elements as functions of time can accurately describe perturbations of the orbits of solar system bodies for limited time intervals. For longer intervals, the series must be recalculated. 

The Cassim-Huygens spacecraft consists of two parts. Cassini is the orbiter, designed to attain orbit around Saturn, while Huygens is a space probe, designed to be released into the atmosphere of the planet s moon, Titan. NASA was responsible for the design and construction of the Cassini orbiter, while ESA was responsible for the Huygens probe. 

Mercury orbits closest to the sun, followed by Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Neptune is farthest from the Sun for 20 of every 248 years. Planets will never collide because one is always higher than the other, even when their orbits do intersect. 

The geocentric Ptolemaic system was superseded by the heliocentric system of Copernicus (1473-1543) principally owing to the work of Galileo, Kepler, and Newton in the seventeenth century. The planets are now known to revolve about the sun in elliptical orbits of small eccentricity at the following mean distances (in millions of miles)—Mercury, 36 . Venus, 67-2 Earth, 92-9 Mars, 141 5 Jupiter, 483 3 Saturn, 886 1 Uranus, 1783 Neptune, 2793 Pluto, 3666. 

JASON Ast. Hypothetical planet, claimed by WEMYSS 1927 to be ruler of zodiacal Sagittarius and to be in orbit between Saturn and Uranus JL... 

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