An ice giant is type of giant planet composed largely of materials less volatile than hydrogen and helium. It became known in the 1990s that Uranus and Neptune were really a distinct class of giant planet, composed of about 20% hydrogen, compared to the heavier gas giant's 90%. They are thought to lack metallic hydrogen at their cores, instead, mostly heavier elements including supercritical water.
In March 2012, it was found that the compressiblity of water used in ice-giant models could be off one third. The value is important for modeling ice giants, and has a ripple effect understanding of them. Ice giants include Uranus, Neptune, and exoplanets so categorized.
Famous quotes containing the words ice and/or giant:
“Sole and self-commanded works,
Fears not undermining days,
Grows by decays,
And, by the famous might that lurks
In reaction and recoil,
Makes flames to freeze, and ice to boil.”
—Ralph Waldo Emerson (1803–1882)
“Of a truth, Knowledge is power, but it is a power reined by scruple, having a conscience of what must be and what may be; whereas Ignorance is a blind giant who, let him but wax unbound, would make it a sport to seize the pillars that hold up the long- wrought fabric of human good, and turn all the places of joy as dark as a buried Babylon.”
—George Eliot [Mary Ann (or Marian)