Chapter 3, The Solar System
The solar wind can interact with Earth's magnetic field to create powerful electric currents that cause near the poles
. auroras
Scientists think the solar system formed about
4.6 billion years ago.
Uranus's axis is tilted at an angle of about ____ degrees from the vertical.
90
comet
A ball of frozen dust and rock that orbits the sun and has a tail that glows
meteoroid
A chunk of rock or dust in space
sunspot
A dark area of gas on the sun's surface that is cooler than surrounding gases.
The solar system formed from
A giant cloud of gas and dust
planet
A large body in space that orbits a star and does not produce light of its own
prominence
A loop of gas that protrudes from the sun's surface, linking parts of sunspot regions
meteorite
A meteoroid that has hit earth's surface.
Geocentric
A model of the universe in which Earth is at the center of the revolving planets and stars.
Kuiper Belt
A region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice
radiation zone
A region of very tightly packed gas in the sun's interior where energy is transferred mainly in the form of light.
Ellipse
A regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.
Oort Cloud
A spherical region of comets that surrounds the solar system
meteor
A streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere.
solar wind
A stream of electrically charged particles produced by the sun's corona
ring
A thin disk of small ice and rock particles surrounding a planet.
astronomical unit
A unit of length used for distances within the solar system
dwarf planet
An object that orbits the sun and is spherical, but has not cleared the area of its orbit.
Heliocentric
Based on the belief that the sun is the center of the universe
nucleus
Control center of the cell
The fact that each planet's orbit is an ellipse was discovered by
Copernicus.
All the gas giants' atmospheres are made up primarily of helium and oxygen.
False
An octagon is an oval shape, such as the planets' orbits.
False
Earth is unique in our solar system for having liquid mercury on its surface.
False
Galileo discovered six moons around Jupiter.
False
Helios is the Latin word for "Sun."
False
In ancient times, people could not accept that the Sun was the center of the universe.
False
Mercury rotates so slowly that its day is longer than its year.
False
Space telescopes such as Cassini have revealed many details of the outer planets.
False
Temperatures decrease tremendously from the outer to inner layers of the gas giants.
False
The inner planets are small and dense and have smooth surfaces.
False
The thick clouds on Venus are made up mostly of carbonic acid droplets.
False
Uranus is three times as far from the Sun as Saturn, so it is much colder.
False
he arrangement of the known planets and how they move around the Sun was first worked out by
Galileo Galilei.
About three fourth's of the Sun's mass is
Hydrogen
People became convinced that the heliocentric model is correct after evaluating evidence collected by
Johannes Kepler.
All the known dwarf planets except Ceres orbit in the
Kuiper belt.
All the inner planets have an atmosphere except
Mercury.
Earth is at the center of the revolving planets and stars in a(n)
Model
greenhouse effect
Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases
planetesimal
One of the small asteroid-like bodies that formed the building blocks of the planets.
Most comets originate in the
Oort cloud.
once the ninth planet in the solar system, is now considered a dwarf planet.
Pluto
About 99.85 percent of the mass of the solar system is contained within the
Sun
chromospere
The middle layer of the sun's atmosphere
corona
The outer layer of the sun's atmosphere.
Covection Zone
The outermost layer of the sun's interior.
A few scientists believe that Saturn's largest moon , may support life.
Titan
Ge is the Greek word for "Earth."
True
Neptune's blue color comes from methane in its atmosphere.
True
Oxygen makes up about 20 percent of Earth's atmosphere.
True
Ptolemy's model explained the motions observed in the sky fairly accurately.
True
In the late 1500s, Ptolemy's observations were supplanted by those of
Tycho Brahe.
The inner planets that experience a greenhouse effect are
Venus and Earth.
The heliocentric system gained support when Galileo observed that
Venus goes through phases similar to those of Earth's moon.
nuclear fusion
a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
gas giant
a planet that has a deep, massive atmosphere, such as Jupiter, Saturn, Uranus, or Neptune
asteroid
a small rocky body orbiting the sun
Between Mars and Jupiter is a region of the solar system called the
asteroid belt
Most asteroids orbit the Sun in the
asteroid belt.
Scientists use the meter light year to measure distances within the solar system.
astronomical unit
One day is the time it takes a planet to rotate on its
axis
Mars's atmosphere is composed mostly of
carbon dioxide.
Clouds of gas and dust on a comet form a fuzzy outer layer called a(n)
coma
A chunk of ice and dust whose orbit is usually a long, narrow ellipse is a
comet
What layer are you looking at when you look at an image of the Sun?
corona
You see the when you look at an image of the Sun.
corona
Pluto was recently reclassified as a(n)
dwarf planet
The four outermost planets in the Sun's orbit are mostly made of liquid and
gas
Because the four outer planets are so large, they are often called
gas giants
The solar system began to form as ______ pulled rock, ice, and gas together.
gravity
When a meteoroid enters Earth's atmosphere, friction causes it to burn up and produce a streak of light called a(n)
meteor
If a meteoroid hits Earth's surface, it is called a
meteorite
A chunk of rock or dust in space that usually comes from a comet or an asteroid is called a
meteoroid
All but two planets in the solar system have a natural satellite, or
moon
All the outer planets have many which range in number from 13 to greater than 60.
moons
The Sun produces energy by
nuclear fusion
You see the middle layer of the Sun's atmosphere, the , at the start and end of a total eclipse.
photospere
The Sun produces energy through
photovoltaic cells.
Small asteroid-like bodies that became the building blocks for the planets are called
planetesimals.
Huge loops of gas that link different parts of sunspot regions are called
prominences.
The Sun's layers, from innermost to outermost, are the core, and convection zone
radiation zone
terrestrial
relating to the land
A is a thin disk of small particles of ice and rock.
ring
Large eruptions of gas from the Sun out into space are called
solar flares.
Planetesimals collided, stuck together, and eventually combined to form all the other objects in the
solar system.
The corona sends out a stream of charged particles called the
solar wind
The Sun is a(n)
star.
coma
state of profound unconsciousness
In a heliocentric system, Earth revolves around
sun
solar system
sun, planets, and all the other objects that revolve around the sun
Areas of gas on the Sun's surface that are cooler than the gases around them are called
sunspots.
core
the central part of the Earth below the mantle; also the center of the sun
asteroid belt
the region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found
Photosphere
the visible surface of the sun
Some regions of Mars have giant
volcanoes.
