23-3 Flashcards
(22 cards)
What did NASA’s Cassini study?
Cassini: orbiter exploring Saturn, part of international cooperation.
Created a natural-color image by stitching smaller images together.
what are key characteristics of outer planets?
Strong gravity holds thick gas atmospheres. Hydrogen and helium become liquid under pressure. Cold outer layers, hotter interiors. All gas giants have many moons and ring systems
what is a ring?
a thin disk of small particles of ice and rock
What are the key characteristics of Jupiter?
Largest, most massive, and fastest rotating planet. very short days, very long years. Visible to the naked eye due to its size and brightness.
What is Jupiter’s structure and atmospheric composition?
Atmosphere: H and He into liquid, with ammonia, methane, sulfur, and water vapor. Liquid H turns into metallic hydrogen under pressure, with a rocky core beneath. Cloud bands form swirling storms. Emits twice as much heat as it receives due to convection currents and high-speed winds.
what is the Great Red Spot? why does it not go away?
most spectacular of storms on Jupiter, larger than Earth, with speeds of hurricanes, does not go away because no land to dissipate storms, lightning observed
What are the key characteristics of Jupiter’s moons? Who found them, and name them and describe.
50 moons, 14 provisional moons, Some moons orbit larger moons of Jupiter. Galileo discovered first four, all larger than Earth’s moon:
Io: Closest large moon, tidal forces cause volcanic eruptions.
Europa: Rocky. thick ice crust; cracks suggest water beneath.
Ganymede: Largest moon in solar system
Callisto: Heavily cratered of ice and rock
What are Jupiter’s rings made of, and how were they formed?
Discovered by Voyager 1, faint, made of small dark particles, Believed to be fragments from meteorite impacts on Jupiter’s moons.
what are key characteristics of Saturn?
Sixth planet from the Sun, second-largest planet, Known for rings first noticed by Galileo, has the lowest density (could float on water). very long years, short days
what is the atmosphere like on Saturn? what are the layers like?
Thick atmosphere: mostly hydrogen and helium, with ammonia, methane, and water vapor.
Deep layers: liquid hydrogen and helium, with a rock and ice core.
what are the 4 features of Saturn Voyager I and II discovered? what did Cassini discover?
- Atmosphere very active with fast winds
- Large cyclonic “storms” exist, but smaller
- Eleven additional moons
- Rings of saturn are more complex than what was expected
Cassini probe discovered lots about rings and more moons
What did Voyager discover about Saturn’s rings?
made of 20 rings, not just 3, consist of ice and rock particles of various sizes, debris from broken moons, asteroids, and space objects
ring system is most complex of any outer gas giant planet - tings A and B: dense, varied particle sizes, Faint E ring made of fine, widely dispersed particles.
What are some key facts about Saturn’s moons? what is its largest moon?
53 moons, 9 provisional moons. Tita is largest moon, bigger than Mercury, thick atmosphere, liquid methane on surface
What are some key characteristics of Uranus?
Seventh planet from the Sun, twice as far from the Sun as Saturn, much colder, 4 times Earth’s size, 14 times more massive. Very long yearss, 17-hour east-west rotation, axis is tilted on its side, possibly from a past collision. Discovered by William Herschel
What is Uranus’s atmosphere and structure like?
Mostly H, He, methane, giving it a blue-green color.
Beneath atmosphere –> liquid –> metallic hydroggen –> with icy core
Voyager 2 revealed 9 rings, 27 moons, and tilted magnetic field. Some moons cratered, others smooth.
What are the key characteristics of Neptune?
Eighth planet from Sun, similar to Uranus, Long years, shorter days.
Atmosphere: Methane gives it a blue-green color and features storm-like characteristics, including the Great Dark Spot, which disappeared after 5 years
What are some unique features of Neptune’s atmosphere?
Cirrus-like clouds made of frozen methane, Possible liquid water, methane, and ammonia beneath the atmosphere.
Thin nitrogen atmosphere with methane geysers.
Coldest surface temperature in the solar system.
What did Voyager II discover about Neptune’s moons and rings? What was its largest moon, how was Neptune predict?
discovered faint rings and 6 new moons, Triton is Neptune’s largest moon. Neptune was predicted mathematically due to Uranus’s irregular orbit.
What is Pluto’s size and characteristics?
Once considered the ninth planet, Pluto smaller than Earth’s moon.
has solid, rocky surface, no dense atmosphere. Some believe it may have been a moon of Neptune. Pluto’s highly elliptical orbit causes ice to thaw and form thin atmosphere when closest to sun
Why was Pluto reclassified as a dwarf planet? what is the definition of a planet?
According to the IAU’s new definition of a planet:
1. A celestial body that orbits Sun.
2. Sufficient mass and gravity to form a nearly round shape
3. Gravitational force to clear space debris around orbit - Pluto doesn’t clear orbit’s neighborhood, so dwarf planet.
what is a dwarf planet compared to the definition of a planet?
1 and 2 - same as planet (celestial body that orbits sun, sufficient mass and gravity to form nearly round shape) 3. Doesn’t clear the neighborhood around orbit, 4. Not a satellite of another planet
what are other dwarf planets?
Ceres: in asteroid belt
Eris: similar size to Pluto slower orbit, long years
Charon: Pluto’s large moon, diameter equal to half of Pluto’s, because of close size and orbit, Charon and Pluto often considered double planet
