What are ice giants?
Q: What are ice giants?
A: Ice giants are huge planets made mostly of elements heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur.
Q: How many ice giants are in the Solar System?
A: There are two known ice giants in the Solar System - Uranus and Neptune.
Q: What is the definition of "ice" in astrophysics and planetary science?
A: In astrophysics and planetary science the term "ice" refers to volatile chemical compounds with freezing points above about 100 K (−280 °F; −173 °C), such as water, ammonia, or methane.
Q: How does the composition of ice giants compare to that of gas giants?
A: Ice giants consist of only about 20% hydrogen and helium in mass, whereas gas giants like Jupiter and Saturn are both more than 90% hydrogen and helium in mass.
Q: When were Uranus and Neptune discovered to be a distinct class from other giant planets?
A: It was realized that Uranus and Neptune were a distinct class of giant planet different from other giant planets like Jupiter and Saturn during the 1990s.
Q: What form is most of the water on Uranus & Neptune found in today?
A: Most of the water on Uranus & Neptune is found today as a supercritical fluid at temperatures & pressures inside them rather than being frozen into an icy form.
