Composition and Structure
With a mass of 1.0243×1026 kg, Neptune is an intermediate body between Earth and the larger gas giants: its mass is seventeen times that of the Earth but just 1/19th that of Jupiter. The planet's surface gravity is only surpassed by Jupiter. Neptune's equatorial radius of 24764 km is nearly four times that of the Earth. Neptune and Uranus are often considered a sub-class of gas giant termed "ice giants", due to their smaller size and higher concentrations of volatiles relative to Jupiter and Saturn. In the search for extrasolar planets Neptune has been used as a metonym: discovered bodies of similar mass are often referred to as "Neptunes", just as astronomers refer to various extra-solar bodies as "Jupiters".
Read more about this topic: Neptune
Famous quotes containing the words composition and/or structure:
“When I think of God, when I think of him as existent, and when I believe him to be existent, my idea of him neither increases nor diminishes. But as it is certain there is a great difference betwixt the simple conception of the existence of an object, and the belief of it, and as this difference lies not in the parts or composition of the idea which we conceive; it follows, that it must lie in the manner in which we conceive it.”
—David Hume (1711–1776)
“Each structure and institution here was so primitive that you could at once refer it to its source; but our buildings commonly suggest neither their origin nor their purpose.”
—Henry David Thoreau (1817–1862)