Like granitas and other ices, sorbet can be made without an ice cream maker. Like Pluto's, Triton's crust consists of 55% nitrogen ice with other ices mixed in. Volatile materials, for example ices, evaporate quickly. Trace ices include 0.1% methane and 0.05% carbon monoxide. The amount of deuterium in the comet's water ices was determined through spectroscopic observations. The other 1% is dust particles, thought to be mainly graphite, silicates, and ices. Lab experiments on the photochemistry of simple interstellar ices have produced amino acids. Some additional volatile ices such as ammonia may also be present. The atmosphere of Uranus is composed primarily of gas and various ices. A man (Terry Jones) approaches her and asks for two choc ices. The interior of Uranus is mainly composed of ices and rock. Tracks may be used on sand, ices and snow. Sputnik Planitia likely originated as an impact basin that subsequently collected volatile ices. Spin ices are geometrically frustrated magnetic systems. Beyond the frostline volatile ices are generally more common.