Chapter 23: Touring Our Solar System

What is the order of the planets from the inside out?

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.

How did the solar system form according to the nebular theory?

From a huge rotating cloud of dust and gas (nebula) that contracted, spun faster, and flattened into a disk.

What is accretion in the formation of the solar system?

The process where solid bits of matter collided and clumped together to form planetesimals.

What difference in composition exists between inner and outer planets?

Inner planets are rocky/metallic; outer planets are gas/ice giants with thick atmospheres.

Why are the inner planets composed of high-melting-point materials?

Proximity to the Sun meant extreme heat allowed only metals and silicate minerals to condense.

Why were the outer planets able to become gas giants?

Frigid temperatures allowed ices to form, and their massive size let them gravitationally capture light gases.

What are the extreme temperature variations on Mercury?

Daytime temperatures reach 427°C and nighttime plunges to -173°C.

What is Mercury's atmosphere like?

Practically nonexistent; it reflects only 6% of sunlight.

What are the key surface features of Mercury?

A densely cratered surface crossed by long scarps formed as the planet cooled and shrank.

How many moons does Mercury have?

0 moons.

What causes Venus's extreme surface temperature of 475°C?

A hostile, runaway greenhouse effect driven by a 97% carbon dioxide atmosphere.

What is the surface atmospheric pressure on Venus?

90 times that of Earth.

What is Venus's surface primarily composed of?

Volcanic plains (80%) and highlands (8%) reshaped by extensive basaltic volcanism.

How many moons does Venus have?

0 moons.

What is Earth's atmospheric composition primarily made of?

Nitrogen and oxygen.

How many natural satellites does Earth have?

1 natural satellite (the Moon).

What is Mars's climate and average temperature like?

A cold desert climate with average temperatures between -70°C and -100°C. also has dust stroms

What gives Mars its reddish surface color?

Iron oxide.

Name two prominent surface features on Mars.

Olympus Mons (shield volcano) and Valles Marineris (massive canyon system).

How many moons does Mars have?

2 small, irregularly shaped moons: Phobos and Deimos.

What powers Jupiter's massive convection currents and internal heat?

It gives off nearly twice as much heat as it receives from the Sun.

What is Jupiter's Great Red Spot?

A centuries-old cyclonic storm.

What happens to hydrogen deep inside Jupiter due to extreme pressure?

It turns into a liquid ocean and deeper down into liquid metallic hydrogen.

What are Jupiter's four large Galilean moons?

Io, Europa, Ganymede, and Callisto.

What is unique about Saturn's density?

Its average density is 0.7 g/cm³; it is less dense than water and would float.

What are Saturn's rings primarily made of?

Ice and rock moonlets.

What is Saturn's largest moon?

Titan, which possesses a dense atmosphere.

What gives Neptune its vibrant blue color?

Methane in its thick atmosphere.

What is Neptune's largest moon, which exhibits retrograde motion?

Triton.

What is unique about Uranus's axis of rotation?

It rotates on its side with a tilt greater than 90 degrees.

What is Pluto's composition best described as?

A 'dirty iceball' of frozen gases with small amounts of rocky material.

What is Pluto's primary moon?

Charon.

What are three main effects of a planet having an atmosphere?

Temperature regulation (greenhouse effect), surface protection/weathering, and albedo/light reflection.

What is a planetesimal?

A small, irregularly shaped solid body formed during the early solar system by accretion.

What modern remnants represent planetesimals?

Asteroids, comets, and large captured moons.

many of them found in kuplers belt

What is an Astronomical Unit (AU)?

The average distance from the Earth to the Sun (approx. 150 million km).

Where is the asteroid belt located?

In the region between the orbits of Mars and Jupiter.

What are asteroids typically made of?

Silicate rocks and metallic materials like iron and nickel.

What is a meteoroid?

A small solid particle traveling through space.

What is a meteor?

A meteoroid that enters Earth's atmosphere and burns up, creating a streak of light.

What is a meteorite?

A meteoroid that survives passage through the atmosphere and strikes Earth's surface.

What defines a planet's day?

The time it takes to complete one full rotation on its axis.

What defines a planet's year?

The time it takes to complete one full revolution around the Sun.

Where can liquid water oceans be found beneath the surface in the outer solar system?

Beneath the icy crust of Europa (Jupiter's moon).

What is an Earth-crossing asteroid called?

A Near-Earth Asteroid.

What percentage of the solar system's mass does the Sun contain?

99.85%.

What are the three main structural parts of a comet?

Nucleus, coma, and tail.

What two solar forces shape a comet's tail and push it away from the Sun?

Radiation pressure and solar wind.

Where do short-period comets originate?

The Kuiper Belt.

Where do long-period comets originate?

The Oort Cloud.

What is Halley's Comet orbital period?

Approximately 76 years.

What causes annual meteor showers?

Earth passing through a swarm of comet debris along its orbit.

What caused the global extinctions 65 million years ago?

A roughly 10 km asteroid impact.

Temo of venus

475 C

Venus atompophre

97 % carbon dioxide with traces of water and nitrogen

Who is earths twin

Venus

mars atomosphere

thin 1% density of earths

Widnest planet

neptune

which palnets have rings

all jovian planets: juptier, saturn, uranus, neptune

about how many moons does jupiter have

115

satuarns moons

293

largest and most massive moon

Ganymede is the largest and most massive moon in the solar system. It orbits Jupiter as one of its four Galilean moons. [1, 2, 3]

saturn weather

cyclone stoems, 1500 k winds

saturn atoposphere

hydroden, heliem, mathanse, ammonia (thick)

neptune storm

great dark spot

great red spot

The Great Red Spot belongs to Jupiter.

moon of neptune

16

uranas moons

27 moons

astiord

small rocky body orbiting sun

where can water be found in ss

earth, mars (traces), moons( europea0 and tirian w ice, comets frozen water ice

how do you stop an astriod from impacting warth

deflecting it away by force or pushing

coma

a small glowing nuclues with a diamer of only a few km 9 point away from sun)

kuipee belt

comets that obit beyond neptune region

oort cloud

cpmets distribiyed from the sun forming a spherical shell aroufn solor system

most mereuod origina from

interplaniatrt debris, matireal from astriod belt, rthe solid remains of comets taht once traveled near earth orbit

what is more inpotent of an astroid velocity of size

velocity v²