Mars/Neptune

J In outer space, frozen water, or ice, has been found on the moon, on planets— particularly Mercury, Mars, Neptune, and Pluto—and in comets and clouds between stars in our galaxy. Recent explorations of Mars indicate that there may be liquid water underground on Mars.This means there could be microorganisms living there ... 

Our solar system consists of the Sun, the planets and their moon satellites, asteroids (small planets), comets, and meteorites. The planets are generally divided into two categories Earth-like (terrestrial) planets—Mercury, Venus, Earth, and Mars and Giant planets—Jupiter, Saturn, Uranus, and Neptune. Little is known about Pluto, the most remote planet from Earth. 

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. 

Hydrogen isotopic compositions, expressed as molar D/H ratios, of solar system bodies. The relatively low D/H values in the atmospheres of Jupiter and Saturn are similar to those in the early Sun, whereas D/H ratios for Uranus and Neptune are intermediate between the Jupiter-Saturn values and those of comets and chondrites. The Earth s oceans have D/H shown by the horizontal line. Mars values are from SNC meteorites. Modified from Righter et al. (2006) and Lunine (2004). 

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...

When thinking about how our solar system may have evolved from proplyds (protoplanetary disks), we must remember that the violence of the early Solar System was tremendous as huge chunks of matter bombarded each other. In the inner Solar System, the Sun s heat drove away the lighter-weight elements and materials, leaving Mercury, Venus, Earth, and Mars behind. In the outer part of the system, the solar nebulas (gas and dust) survived for some time and were accumulated by Jupiter, Saturn, Uranus, and Neptune. 

But what was there, in addition to water, on the primitive Earth The four outer planets of the solar system (Jupiter, Saturn, Uranus and Neptune) are still made up mainly of hydrogen, helium, methane, ammonia and water, and it is likely that those same chemicals were abundant everywhere else in the solar system, and therefore even in its four inner planets (Mercury, Venus, Earth and Mars). These were too small to trap light chemicals, such as hydrogen and helium, but the Earth had a large enough mass to keep all the others. It is likely therefore that the Earth s first atmosphere had great amounts of methane (CH4), ammonia (NHJ and water, and was, as a result, heavy and reducing, like Jupiter s. 

Body Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto... 

At the time, more than a dozen planetary satellites had already been discovered for Jupiter, Saturn, Uranus, and Neptune. None had been found for Venus or Mercury, nor were they likely to be found, given the proximity of these planets to the Sun. Mars likewise had no satellites. .. or, at least, none that had yet been discovered. 

The solar system is sometimes divided into two parts consisting of the inner planets—Mercury, Venus, Earth, and Mars—and the outer planets—Jupiter, Saturn, Uranus, Neptune, and, until recently, Pluto. One might imagine that understanding the chemical and physical properties of the inner planets would help in understanding the chemical and physical properties of the outer planets. No such luck. The two groups of planets differ from each other in some fundamental and important ways. 

The composition of the outer planets is also very different from that of the inner planets. Mercury, Venus, Earth, and Mars are all made of rocky-like material with a density of about 5.5 g/cm3. By contrast, the outer planets seem to consist largely of gases (which accounts for their sometimes being called the gas giants) with densities of about 0.69 g/cm3 for Saturn to 1.54 g/cm3 for Neptune. These... 

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 effects of condensation are also seen in the bulk compositions of the planets and their satellites. The outer planets, Uranus and Neptune, have overall densities consistent with their formation from icy and stony solids. The satellites of Uranus have typical densities of 1.3g/cm, indicative of a large ice component. The inner planets have uncompressed densities ranging from 3.4 for Mars to... 

The chapters in this part help fill in those blanks. Chapter 8 illuminates the Moon and the Nodes of the Moon in all 12 signs. Chapters 9 and 10 discuss Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto — plus the asteroid Chiron, which was discovered in 1977 and is now routinely included in horoscopes by many astrologers. Chapter 11 talks about the Ascendant, and Chapter 12 describes the influence of the planets in each of the houses. Finally, Chapter 13 looks at the way the planets interact by analyzing the aspects, or geometrical relationships, that link them together. 

In Chapters 16, 17, and 18,1 tell you how to squeeze the maximum benefit out of astrology. Chapter 16 explains how the current positions of Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto affect you — and what you can look forward to in the future. 

The sign that the Sun occupied at the moment of your birth is the most basic astrological fact about you. It defines your ego, motivations, needs, and approach to life. But the Sun isn t the only planet that affects you. (For astrological purposes, both luminaries — the Sun and the Moon — are called planets. Do yourself a favor and don t use this terminology when talking to astronomers.) Mercury, Venus, Mars, Jupiter, Saturn, Chiron, Uranus, Neptune, and Pluto, not to mention the Moon, represent distinct types of energy that express themselves in the style of the sign they re in. 

The Sun, the Moon, and the planets are substantial, massive objects. Whether they re solid and rocky like the Moon and Mars, or gas giants like Jupiter and Neptune, they re distinct, visible worlds with their own geography and... 

I m partial to the second, more mundane symbol, which has its origins in the world of science. That symbol (see Figure 10-3) represents both the first two letters of Pluto s name and the initials of the aristocratic astronomer Percival Lowell, who was so convinced that there was life on Mars that he built an observatory in Arizona for the sole purpose of observing it. At the same time, he devoted himself to a search for the mysterious Planet X, which he believed was revolving around the sun in the outskirts of the solar system, way past Neptune. He never found it. But 14 years after Lowell s death, Clyde Tombaugh worked doggedly at the Lowell Observatory and discovered Pluto. This symbol acknowledges Lowell s contributions. 

I consider the planets in this order first the Sun and Moon, then the planets in order of their distance from the Sun Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. When looking up an aspect, be sure to look for it under the planet that comes first in the list. An aspect between Mercury and Uranus, for example, appears under Mercury an opposition between Venus and Pluto is discussed under Venus, and so on. 

Dreamy Neptune can spend the day in foggy reverie, while heedless Mars takes action (however ill-thought out or ineffective). Fortunately, Mars also fuels Neptune s creative plans. 

---