Resemblances between swifts and swallows are due to convergent evolution, reflecting similar life styles based on catching insects in flight. The family name, Apodidae, is derived from the Greek á¼ÏÎ¿ÏÏ (Ã¡pous), meaning footless, a reference to the small, weak legs of these most aerial of birds.
Does Saturn have an atmosphere and what does it consist? The planet Saturn does have an atmosphere, and indeed, it consists mostly of atmosphere. The main chemical constituents of the atmosphere of Saturn are methane, ammonia, and hâ¦ydrogen. 5 people found this useful.
Saturn is a gas giant, meaning it is mostly composed of an upper layer of gases such as molecular helium and hydrogen surrounding a hot rocky core. Because of this, although Saturn is 95 times larger than Earth, its density is only 0.7 that of water. Saturnâs atmosphere is composed of some 75% of hydrogen and 25% helium along with small amounts of other substances such as methane and water ice. The planet is surrounded by clouds, with the upper layer composed of ammonia ice clouds and where temperatures can reach as low as -250Â° C. Below this layer is a lower deck of ammonium hydro-sulfate clouds, with average temperatures rising to -70Â° C.