ONeill Colonies and Orbiting Cities

Even if human beings haven't physically traveled very far into the Solar System a mere 0.002 AU from home8 the human imagination has traveled to the very edges of the universe (and in some cases far beyond). Although one could argue that the political motivation and initial drive to place the first astronauts in space and then on the Moon was misguided (see Vignette E at the end of Chapter 7 in this book), the Mercury, Gemini, Apollo, Vostok, and Soyuz missions mark, nonetheless, a tremendous...

The End of the Biosphere

At the end of Chapter 4 we cast our gaze billions of years into the future and looked at the effects of an aging Sun upon the Earth. The prognosis was not good. As the Sun ages, so its luminosity will increase, and this will drive up the effective temperature term Tp given by Equation (5.1) , and the Earth's surface temperature will rise. However, since the weathering of silicate rocks proceeds more rapidly at higher temperatures, so the atmospheric CO2 concentration will be drawn down via, for...

Home on the Range A Brief History of the Solar System

Astronomers only slowly warmed to the Copernican hypothesis. Indeed, Copernicus having had absolutely no proof or way to demonstrate the truth of his claim that Earth moved about the Sun, practicing astronomers had no good reason to adopt his strange new ideas. Inevitably, however, those with inquiring minds were won over, and the detailed workings of the Solar System, as we would come to call it, began to emerge. However, it was a complex scientific and sociological struggle, and many...

The Coming of a Second

From Earth, Jupiter is one of the resplendent jewels of the night sky. After the Sun, Moon, and Venus, it is the brightest nighttime ''star'' that we can see. Moving sedately through the zodiacal constellations once every 12 years, it shines on us with a quicksilver light. In the distant future, however, it might shine on our descendants with an even greater intensity, and, even more importantly, it might also illuminate its accompanying moons. Jupiter weighs in at about 1 1,047 the mass of the...

Albedo Change and Increased Insolation

The amount of solar energy absorbed by Mars is determined according to the albedo of its atmosphere and surface. As indicated by Equation (5.1), the smaller the albedo term, the greater the amount of solar heating that takes place. Table 6.2 below indicates the effect of varying the atmospheric albedo of Mars. It is highly likely that solar shades will play an important role in future attempts to moderate the increases in the Earth's temperature as a result of natural warming cycles, the Sun's...

The Galilean Moons Food for Thought

Of all the Jovian moons, Europa has perhaps attracted the most attention from astronomers and astrobiologists in recent years. Indeed, it is a world that has repeatedly revealed unexpected marvels. Being some 3,161 km across Europa is just a little smaller than our Moon. Unlike the Moon, however, it has a remarkably smooth surface devoid of upland regions and impact craters. The most prominent features are long, looping chains of dark ridges and deep fissures that stretch across its surface,...

Supramundane Planets and Shell Worlds

In contrast to the low-gravitational environment that exists on Ceres, the gravitational acceleration in the outer atmosphere of Jupiter is 2.53 times greater than that experienced on the Earth. British engineer Paul Birch has suggested, therefore, that a vast honeycombed shell might be built around Jupiter at a stand-off distance of 42,000 km from the upper cloud deck. Such a suprajupiter structure, as Birch calls it, would have a surface gravity the same as that on Earth, and a surface area...

We the Tikopia

It is a small conical extrusion above the Pacific Ocean. Situated at the far-eastern end of the Solomon Islands chain, it is home to just over 1,000 islanders. Its nearest neighboring islands are 140 km away, the isolation of Tikopia is almost absolute, and it is only rarely visited by supply ships and adventuring mariners. From above, Tikopia is nearly elliptical in profile, being about twice as long as it is wide. The middle one-third of the island is...