A Street Cat Named Bob is the autobiography of James Bowen's life on the street, and the story of the friend he find's in a cat he names Bob. I must admit Bob never stops amazing me in this book, he is so intelligent and loyal! I'd love to meet him myself and I can see why everyone who encounters Bob loves him, too.
The Silurian atmosphere shows a decline from carbon dioxide values of 1200 ppm in the Upper Ordovician. Budyko and others (1987) (see Fig. 8) indicated atmospheric oxygen declines from about 65 percent of PAL (Present Atmospheric Level) to about 35 percent of PAL in the Late Silurian.
In the top one-fourth of the planet, the pressure and temperature are so high that the hydrogen atoms are stripped of their outer electrons, forming a liquid metal. Like Jupiter, Saturn has a thick atmosphere composed of hydrogen and helium. The ratio of hydrogen to helium ratio decreases with depth. Methane and ammonia are also present. The atmosphere of Saturn envelops a thick layer of metallic hydrogen. The atmosphere of Neptune consists mainly of hydrogen and helium, but about 2.5-3% of the atmosphere is methane. Like Uranus, clouds in Neptune's atmosphere are composed of crystals of methane. -=-=-=-=- Since gas giants do not actually have a surface, it is rather difficult to determine where their atmospheres end.