Lecture 13 Flashcards
In planetary science the term “ice” refers to
volatile
compounds with freezing points above ~ 100 K (-173°C)
Ice giants are _______ than gas giants
smaller
The ice giants in our solar system are?
Uranus and Neptune.
Uranus and Neptune consist of about ______ Hydrogen(H) and Helium(He) by mass.
20%
Jupiter and Saturn, which are
more than ___ H and He by mass
90%
referred to as “ice giants” because
they are comprised mainly of a
hot dense fluid of “icy” materials
What are the hot dense fluid of “icy” materials of Uranus and Neptune
water(H20), methane(CH4), and ammonia(NH3) above a small rocky core
Gas Giants have _____ H/He atmospheres
Thicker
Ice Giants have _____ H/He atmospheres
Thinner
Gas Giants Atmospheres contain _____ Methane
Very Little
Ice Giants Atmospheres contain ____ Methane
~2%
Gas Giants interior dominated by
metallic hydrogen
Ice Giants Interior dominated by
“ices” water(H20), methane(CH4), and ammonia(NH3)
Ice Giants are of _______ mass while Gas Giants are ____
intermediate, very massive
Gas Giants are how many AU from the sun (astronomical unit)
5-10 AU from sun
Ice Giants are how many AU from the sun (astronomical unit)
20-30 AU from sun
Water is abundant in the outer solar system, and the densities
of the ice giants are very similar to that of _____
water(H2O)
What makes Uranus and Neptune appear blue?
methane
Mantle of ice giants consists of
water(H20), methane(CH4), and ammonia(NH3)
Ice giants atmosphere is consists of
helium, methane gases, hydrogen
Uranus
Orbital Period
(years)
84
Neptune Orbital Period Years
65
Uranus Distance from Sun
(AU) 19.2
Neptune Distance from sun
50 AU
Uranus and Neptune radius
4 x earths
Uranus Mass
14.5 x earth
Neptune Mass
17 earth
Rotation period hours Uranus
17
Rotation period hours Neptune
16
Uranus is the ____ planet from the sun
seventh
Uranus has ____ known moons and ____ known rings
27, 13
Uranus rotates in a ______ direction (like Venus) and its
axial tilt is ___.
clockwise, 98degrees
Theory is a planet-sized body collided with Uranus at a high speed, causing the planet to tilt and giving it its current orientation.
Theories on how the rings around Uranus and Neptune were formed -maintained by the gravitational influence of nearby moons. As the moons orbit their respective planets, they create regions where the gravitational pull is stronger or weaker, which can cause particles in the rings to either clump together or break apart.
the remnants of debris from the collision of large bodies that were disrupted by the planets’ gravity.
material that was left over from the formation of the planets themselves, but that did not accrete into moons
Theories on how the rings around Uranus and Neptune
are maintained
by the gravitational influence of nearby moons. can cause particles in the rings to either clump together or break apart.
The five largest (major) moons of Uranus
are
Miranda, Ariel, Umbriel, Titania, and
Oberon
The major moons of Uranus are
ellipsoidal
four of Uranus’s moons show signs of
internally driven processes such as
volcanism on their surfaces
The largest of the five moons of Uranus is,
Titania, is 1,578km in diameter and the eighth-largest moon in the Solar System
Uranus has __ distinct rings made up of
13, mainly water ice
“core accretion model,” explains how gas giants like Jupiter and Saturn could have
formed
core accretion model struggles to explain the in situ formation of Uranus and Neptune, which are classified as ice giants rather than gas giants. Whats the main issue?
much less massive than Jupiter and Saturn, yet they are still composed primarily of ices rather than gases.
