Chapter 22

When did the solar system begin?

The history of solar system began about 13.7 BILLION years ago with the Big Bang.

How did the Sun and the planets form?

The Sun and planets formed at the same time from a large rotating cloud of interstellar dust and gas called a solar nebula.

What happens when the solar nebula contracts?

A protostar is formed at the center as the solar nebula contracted.

What happens as the remaining material collided and stuck together?

Asteroid sized objects, planetesimals formed.

What are the Terrestrial planets?

Mercury, Venus, Earth, and Mars.
-Shorter years, longer days and fewer moons.

What are Jovian planets?

Jupiter, Saturn, Uranus, and Neptune.
-Longer years, shorter days and more moons.

Planets are composed of what?

-Gases
-Rocks
-Ices

Which planets have atmospheric gases?

Venus, Earth, and Mars.

How does Earth's Moon compare to the Earth?

-It is unusually large compared to its parent planet.
-Similar to Earth's crustal rocks.
-The Moon has a small iron core.
-Gravitational attraction is one-sixth of Earth's.

What is "Maria"?

Is the Latin for "sea", and shows dark regions on the Moon.

What is a highland?

Are bright, densely cratered regions.
-Older than Maria.

What is Ejecta?

Debris that is ejected from a crater.

What are Rays?

Linear features radiating out from a crater.

What is impact theory?

A giant asteroid collided with Earth to produce the Moon.

What are the phases of the Moon's evolution?

1.) Original crust
2.) Highlands
3.) Maria basins
4.) Rayed craters

Mercury overview

-1st planet from the Sun.
-No atmosphere.
-No moons.
-Ice detected in craters at the South Pole.

Venus overview

-2nd planet from the Sun.
-No moons.
-Atmosphere is 97% CO2.
-Greenhouse effect heats the surface to extreme highs.
-Surface pressure is extreme.
-ONLY planet with Retrograde Rotation.

Mars overview

-4th planet from the Sun.
-Called the "Red planet" due to iron oxide in the soil.
-Atmosphere is primarily CO2. (Thin coverage).
-Water ice beneath the surface.
-Extensive dust storms with winds up to 170 MPH.

Mars overview continued.

-Olympus Mons- largest shield volcano in our solar system.
-Valles Marineras- giant canyon larger than the Grand Canyon.

Jupiter overview

-5th planet from the Sun.
-Largest planet. (By a lot).
-Moons discovered by Galilean satellites.
�Banded appearance generated by wind systems blowing in opposite directions.
-Great red spot generated by counterclockwise rotating cyclonic storm.
-Surface t

Jupiter's moons

Callisto- outermost Galilean moon.
Europa- smallest Galilean moon.
Ganymede- largest Jovian satellite.
Lo- most volcanically active body in the solar system.

Europa

-Extremely thin oxygen atmosphere.
-Surface is ice.

Saturn overview

-6th planet from the Sun.
-Average density of 0.7 so it will float in water.
-Rings discovered by Galileo.
-30 named moons.

Titan

Is the LARGEST moon of Saturn.

Enceladus

Moon of Saturn.
-Has an underground sea of liquid water.
-Plumes that spray water ice out from many locations.

Uranus overview

-Axis is inclined at 98' so it rotates on it's sides.
-7th planet from the Sun.

Neptune overview

-8th planet from the Sun.
-Strongest winds in the solar system.
-Great dark spot- counterclockwise.
-Small dark spot- clockwise.

Triton

Largest Neptune Moon.
-The only large moon in the solar system that has a retrograde orbit.

Cryovolcanism

Eruptions are composed largely of water ice, probably mixed with methane and ammonia.

What are the gas giants?

Jupiter, Saturn, Uranus, and Neptune.

What is a dwarf planet?

A dwarf planet is any object orbiting the sun that is not one of the 8 planets.

Why's is the Kuiper belt?

A band of icy objects found beyond the orbit of Neptune.

Pluto overview

-Not visible with the unaided eye.
-Classified as a dwarf planet.
-1 Moon (Charon) discovered in 1978.

Asteroids

-Most lie between Mars and Jupiter.
-Some have very eccentric orbits.

Comets

-Balls of ice, rock, and dust in space with a tail.
-Afrocentrism gases vaporize when near the a sun.

Meteroids

-Called meteors when they enter Earth's atmosphere.
-A meteor shower occurs when Earth encounters a swarm of meteoroids associated with a comet's path.
-Meteoroids are called meteorites when they are found on Earth.

Which characteristic is shared by both the terrestrial and the Jovian planets in our solar system?

Both the terrestrial and the Jovian planets possess a solid core, made mostly of metallic and/or rocky material.

The planets located closest to the Sun are smaller and have high density. How does the nebular hypothesis account for these planets being situated in this position?

The terrestrial planets have small size, high density, and are closest to the Sun because the extremely high temperatures associated with formation allowed only silicate minerals and metals to form solids.

The planets that are farthest from the Sun are the largest bodies in the solar system, but have the lowest average densities. Which is the best explanation for this arrangement of the planets?

The Jovian planets had temperatures that were low enough to allow accumulation of ices, which caused planets of large size.

Anorthosite represents the oldest rock type found on the Moon and is unique because it is primarily composed of a single mineral. What mineral is it?

Plagioclase feldspar.

Which process results in the formation of breccia on the Moon?

Meteorite impacts.

The broad, flat, dark areas, or Maria, seen on the Moon from Earth are composed of which material?

Basaltic lava flows.

Which hypothesis best explains the way scientists think the Moon was formed?

The Moon was formed by ejecta released when a Mars-sized body collided with Earth very early in its history.

The occurrence of crystals in the rocks obtained from the Moon d during Apollo missions indicates that they formed by which process?

Crystallization from a melt.

Earth and the Moon are in extremely close proximity to each other in the solar system. However, in appearance, the Moon exhibits extensive catering, while Earth does not. Which best explains this discrepancy in the appearance of these two bodies?

Earth has an atmosphere, water, and tectonic activity, so most of the craters on Earth have been removed by erosion or eliminated via subduction.

The blue color of both Uranus and Neptune is caused by the presence of which gas in their atmospheres?

Methane.

Which satellite in the solar system exhibits active volcanism?

lo.

Which is the only planet in the solar system whose axis of rotation is in an orientation parallel to its orbital plane?

Uranus.

What evidence observed on Mars indicates that at one time it may have had a warmer climate and a water cycle similar to that on Earth?

Large valleys that resemble river channels.

Saturn's rings are composed of __________.

Lots of individual particles of ice and rock.

Saturn's rings look bright because __________.

Light from the Sun reflects off the material in the rings.

Which of the following statements correctly describes the motion of particles in Saturn's rings?

Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings.

Which of the following statements concerning the moon is true?

The light areas of the moon were formed by small meteor impacts.

Which of the following words would you use to describe a large impact basin?

Basalt.

Which of the following statements regarding volcanoes on Mars is FALSE?

Volcanoes are the most recent surface features on the planet.

Which of the following statements concerning plate tectonics on Earth and Mars is true?

Mars has larger volcanoes than Earth because plate motion is NOT present on Mars.

What causes a central peak to form in an impact crater?

Rebound of the rock layers after impact.

Why is Meteor Crater so well preserved?

Meteor Crater is relatively young.

At what point during a meteorite impact are rock layers overturned?

During the rebound of rock layers after impact.

When did our Solar System begin to form?

5 billion years ago.

How did our Solar System begin to form?

A large cloud of dust and gas began to contract under the force of gravity.

What is a nebula?

A large, diffuse cloud of dust in gas in space.

Where did the energy of the Sun come from originally?

Thermal energy that was converted from the gravitational energy of the original nebula collapse.

What is the nebular theory?

Then theory that explains the formation of the solar system.

Vast, circular to elliptical dark-colored areas on the moon called Maria represent __________.

Very large impact craters filled with basaltic lava.

Which of these lunar features is the oldest?

Lunar highlands.

Rayed craters lik Tyco and Copernicus are known to be younger than the lunar Maria because __________.

Their ejecta, seen as rays, lies across the surface of the Maria.

What is the current accepted hypothesis for the formation of the Moon?

Collision between the Earth and a Mars-sized body.

Where did the rocks of the Moon originate?

The rocks were once part of Earth.

Venus was once called "Earth's twin" because the two planets share many features. However, they also have some startling differences. Which of the following features illustrates how Venus an dEarth differ from each other?

Thick atmosphere.

Why is the Venusian surface so hot?

Because of its dense atmosphere, composed of 97% CO2.

Where are most asteroids found?

Between Mars and Jupiter.

How are asteroids different from comets?

Asteroids are mostly rock; comets are mostly ice.