6th - Science Chaper 21 Outline Flashcards
The _____________ in the solar system orbit the Sun.
Planets
The Sun and the objects that orbit it make up the ______________.
Solar system
The largest object in the solar system is the ____________.
Sun
The Sun is a star made up mostly of ____________ gas.
Hydrogen
_____________ produces enormous amounts of energy in the Sun.
Nuclear fusion
Objects orbit the Sun because it applies ________ forces on them.
Gravitational
Objects that orbit the Sun include planets, dwarf planets, asteroids, and _____________. These objects ___________ the Sun’s light.
Comets, reflect
A planet has nearly ________ shape.
Spherical
There are _____ planets in the solar system.
8
The four planets closer to the Sun are called the ______________ planets.
Inner
Inner planets are made mainly from __________ material.
Rocky
The four planets farthest from the Sun are called the __________ planets.
Outer
Outer planets are made mostly of ice and ______.
Gases
Because the outer planets are much larger than the inner planets, they are sometimes called __________.
Gas giants
A(n) ____________ is a spherical object that orbits the Sun, is not the moon of another planet, and has less mass than any of the eight planets.
Dwarf planets
Millions of small, rocky objects called ___________ orbit the Sun in a bel between Mars and Jupiter.
Asteroids
A(n) _______________ orbits the Sun in an oval-shaped orbit and is made of dust, gas, and ice.
Comets
The __________ is used to measure long distances in the solar system.
Astronomical unit
One astronomical unit (AU) is the average distance from Earth to the _________.
Sun
One way an object in the solar system moves is by orbiting, or _____________ around another planet.
Revolve
The amount of time it takes an object to revolve once around the Sun is its ____________.
Period of revolution
Objects in the solar system also spin, or _________.
Rotate
The time it takes an object to rotate once is its ___________.
Period of rotation
The shape of a planet’s orbit is a(n) __________, which is a stretched-out circle.
Ellipse
The Sun is at one of the __________ of the ellipse, so the distance between a planet and the Sun changes as the planet moves.
Foci
A planet moves __________ when it is closer to the Sun than when it is farther away.
Faster
The mass of a planet is much _________ than the mass of nearby objects.
Larger
The inner planets are those closet to the _________. They are also called the ___________.
Sun, terrestrial planets
The inner planets are made of ___________ and metallic materials.
Rock
The outer layers of the inner planets are in the ___________ state.
Solid
_____________ is the planet closet to the Sun.
Mercury
Mercury has no gases close to its surface, which means it has no ___________.
Atmosphere
Because of its small mass, Mercury’s ___________ is not strong enough to hold gases to its surface.
Gravity
Because Mercury has no wind to move energy from place to place, the temperatures on the side of Mercury facing the Sun are always extremely _______________.
High
Mercury’s surface is covered with impact ___________, smooth plains, and high cliffs.
Craters
Mercury has a core made of ___________ and nickel. It’s mantle is made of oxygen and _________.
Iron, silicon
__________ is the second planet from the Sun.
Venus
Venus ___________ more slowly than it revolves, so a day on Venus is longer than a year on Earth.
Spins/rotates
Unlike most other planets, Venus rotates from ________ to __________.
East, west
Most of Venus’s atmosphere is made up of ______________.
Carbon dioxide
Venus is covered by a thick layer of ____________.
Clouds
The clouds on Venus are made of ___________.
Acid
Venus is the ____________ planet in the solar system.
Hottest
The high temperatures on Venus are caused by the ___________.
Greenhouse effect
The greenhouse effect increases surface temperature because the ____________ traps solar energy.
Atmosphere
Most of the surface of Venus is covered by solidified __________.
Lava
The third planet from the Sun is _________.
Earth
Earth’s atmosphere is made up of ___________ and a mixture of gases.
Water vapor
The atmosphere produces a(n) ____________ that increases Earth’s average surface temperature.
Greenhouse effect
_________________ is supported on Earth because of its atmosphere, large bodies of liquid water, and moderate temperature range.
A variety of life
Earth has a solid inner core and a(n) ________ outer core.
Liquid
The __________ surrounds the outer core.
Mantle
Earth’s crust is broken into large sliding _________.
Plates
Earth’s _________ is made mostly of oxygen and silicon.
Crust
Mars is the ________ planet from the Sun.
Fourth
Mars has _____ small moons.
2
Many probes have examined the surface of Mars; most have looked for signs of __________.
Water
Mars’s atmosphere contains mostly _____________.
Carbon dioxide
Mars’s surface appears to be red because it’s soil contains ______________.
Iron oxide
Ice caps on Mars are made up of ice and frozen _____________.
Carbon dioxide
Features on Mars’s surface include craters, lava flows, canyons, and the largest known ____________ in the solar system.
Mountain
The outer planets are made of materials that are usually ___________ on Earth.
Gases
Gravitational forces produced by the sizes of these planets change gases into __________.
Liquids
___________ is the largest planet in the solar system.
Jupiter
Although it takes 12 years to revolve around the Sun, Jupiter _________ faster than any other planet.
Spins
Jupiter has a system of _________ around it.
Rings
Jupiter’s atmosphere contains helium but it mostly made up of ____________.
Hydrogen
Jupiter’s rotation stretches its clouds into colorful _______________.
Swirling bands
The ______________ on Jupiter is a storm that has lasted more than 300 years.
Great Red Spot
Jupiter’s entire structure is made up of 80 percent hydrogen, about 20 percent ___________, and small amounts of other materials.
Helium
Jupiter has a solid core that is surrounded by __________.
Thick liquid layer
The four largest moon’s of Jupiter are called _____________. These are lo, _________, Ganymede, and Callisto.
Galilean Moons, Europa
Like Jupiter, Saturn rotates __________ and has clouds in bands.
Rapidly
Saturn is mostly made of ____________ and helium.
Hydrogen
Saturn has the largest ___________ system in the solar system.
Rings
Saturn has _________ bands of rings, each of which contains thousands of smaller rings.
Seven
The rings are made mainly of ______ particles.
Ice
Most of Saturn’s moons are small, but one of them, __________, is larger than the planet Mercury.
Titan
Uranus’s atmosphere contains mostly hydrogen and helium, with small amounts of ____________.
Methane
Beneath Uranus’s atmosphere is a slushy layer of water, ________, and other materials.
Ammonia
Uranus might have a rocky ___________.
Solid core
The rotational axis of Uranus is ________ more than that of other planets.
Tilted
Uranus has at least ______ moons and a small ring system.
27
The atmosphere and interior of Neptune are similar to ____________.
Uranus
Neptune has at least _______ moons and a faint ring system.
13
A dwarf planet is a sphere that orbits a(n) __________.
Star
A dwarf planet has objects similar in _______ orbiting near it or crossing its orbital path.
Mass
The dwarf planets in the solar system are _______, Ceres, Eris, Makemake, and Haumea.
Pluto
Ceres is located in the __________ belt. It is the __________ dwarf planet in the solar system.
Asteroid, smallest
Pluto has a rocky core surrounded by _____. It has _________ known moons.
Ice, 3
________ is the largest dwarf planet. It is three times farther from the Sun than the dwarf planet _________ is.
Eris, Pluto
Makemake and Haumea are dwarf planets in the _____________.
Kuiper belt
Asteroids orbit the Sun in a band between _______ and Jupiter.
Mars
The largest asteroid is called _________.
Pallas
Asteroids are chunks of rock and ________.
Ice
Comets are made up of rocks, ice, and _______.
Dust
_________________ between the particles in a comet hold it together.
The gravitational attraction
Comets ________ the Sun in long elliptical orbits.
Orbit
As a comet approaches the Sun, a bright _______ can develop on the comet.
Tail (coma)
The ____________ is the solid, inner part of a comet.
Nucleus
As the comet approaches the Sun, it heats, changing some ice in the nucleus into a(n) __________.
Bright tail
Energy from the Sun pushes gas and dust particles away from the nucleus and makes it _________.
Glow
___________ comets take less than 200 years to orbit the Sun. They usually come from the ______________.
Short-period, Kuiper belt
___________ comets take more than 200 years to orbit the Sun. They come from the ____________.
Long-period, Oort Cloud
A small, rocky particle that moves through space is a(n) ___________.
Meteoroid
As it passes through Earth’s atmosphere, friction with the air makes a meteoroid and the air around it _________.
Hot
A streak of light in the atmosphere mad by a glowing meteoroid is a(n) ____________.
Meteor
Most meteoroids _________ up in the atmosphere.
Burn
A meteoroid that strikes the surface of a planet or a moon is called a(n) __________.
Meteorite
A meteorite can form a bowl-shaped depression called a(n) ____________ in the surface it strikes.
Impact crater
