Our Place in the Solar System Flashcards
Learn the scientific language used in solar system unit
Artifical Satellite
An object that orbits a planet or star and is human-made
The International Space Station is an artificial satellite that orbits Earth.
Asteroid
A large space rock that orbits the Sun
The Asteroid Belt is a large collection of asteroids found between Mars and Jupiter.
Axis
An imaginary line through an object around which it spins
Earth’s axis of rotation passes through the North and South Poles.
Crescent Moon
Any phase when less than half of the sunlit side of the Moon can be seen
A waning crescent moon occurs just before a new moon, and a waxing crescent moon just after.
Day
The time it takes a planet to rotate once
Earth takes 24 hours to rotate once on its axis, while Venus takes 243 Earth days.
Direct Sunlight
Sunlight that hits the Earth’s surface at a high angle
Direct sunlight is more intense and heats the surface more quickly than indirect sunlight.
Eclipse
An event where one object in space blocks another from view
Eclipses occur when the Earth, Moon and Sun are positioned in a straight line.
Equator
An imaginary line halfway between the North and South Poles
The Equator divides the Earth into northern and southern hemispheres.
First Quarter Moon
The phase when the Moon is waxing and half of the sunlit side can be seen
This phase occurs when the Moon is one quarter of the way around its orbit.
Full Moon
The phase when the sunlit side of the Moon is facing towards Earth
A full moon occurs when the Earth is positioned between the Sun and the Moon.
Galaxy
A group of millions or billions of stars
The Solar System is located in the Milky Way galaxy.
Gas Planet
A planet made up mostly of gases, such as hydrogen and helium
Jupiter and Saturn are gas planets.
Geocentric Model
A model of the Solar System in which Earth is at the centre
Many ancient Greek and Roman scientists, such as Ptolemy, believed in this model.
Gibbous Moon
Any phase when more than half of the sunlit side of the Moon can be seen
A waxing gibbous moon occurs just before a full moon, and a waning gibbous moon just after.
Gravity
An attractive force between any two objects that have mass
On Earth, gravity pulls objects towards Earth’s centre. In space, it keeps objects in orbit.
Heliocentric Model
A model of the Solar System in which the Sun is at the centre
This model replaced the geocentric model after Copernicus and Galileo provided evidence for it.
Hemisphere
A half of the Earth, either north or south of the Equator
The United States is in the northern hemisphere.
Ice Planet
A planet made up mostly of icy materials
Uranus and Neptune are ice planets.
Indirect Sunlight
Sunlight that hits the Earth’s surface at a low angle
Indirect sunlight is less intense and heats the surface more slowly than direct sunlight.
Lunar Eclipse
When the Moon passes into the Earth’s shadow
This type of eclipse can only occur during a full moon phase.
Milky way
The galaxy in which the Solar System is located
The Milky Way contains about 100 billion stars.
Model
A representation of an idea, object or system
A scale model accurately indicates the relative sizes of objects, or the distances between them.
Moon
A large natural object that orbits a planet
Earth has one moon, Mars has two and Jupiter has at least 79.
Natural Satellite
satellite
An object that orbits a planet or star and is not human-made
The Moon is a natural satellite of Earth. The Earth is a natural satellite of the Sun.
New Moon
The phase when the sunlit side of the Moon is facing away from Earth
A new moon occurs when the Moon is positioned between the Sun and the Earth.
Orbit
The motion of one object around another because of gravity
The Earth orbits the Sun and the Moon orbits the Earth.
Phase of the Moon
The shape of the sunlit side of the Moon as seen from Earth
The Moon goes through different phases as part of a monthly cycle as it orbits Earth.
Satellite
Any object that orbits a planet or star
The Moon and the International Space Station are both satellites that orbit Earth.
Season
A time of year with typical weather patterns and daylight hours
The Earth’s tilt and orbit around the Sun causes the seasons. In summer, a hemisphere is tilted towards the Sun.
Soalr Eclipse
When the Sun is blocked from view by the Moon
This type of eclipse can only occur during a new moon phase.
Solar System
The Sun and all the objects that orbit around it
The Solar System includes planets, moons, asteroids and other objects.
Star
A ball of gas that releases light and heat
A star is held together by gravity. The Sun is an example of a star.
Summer
A hemisphere experiences this when it’s tilted towards the Sun
Summer is the warmest season, with longer daylight hours and more direct sunlight.
Tides
The regular rising and falling of the sea
Tides are caused by the gravitational pull of the Moon and Sun.
Terrestrial Planet
A planet made up mostly of rock and metal
Mercury, Venus, Earth and Mars are terrestrial planets.
Third Quater Moon
The phase when the Moon is waning and half of the sunlit side can be seen
This phase occurs when the Moon is three quarters of the way around its orbit.
Warning Noon
Any phase when the sunlit side of the Moon appears to shrink over time
The Moon wanes for half of each month, as it changes from a full moon to a new moon.
Waxing Moon
Any phase when the sunlit side of the Moon appears to grow over time
The Moon waxes for half of each month, as it changes from a new moon to a full moon.
Winter
A hemisphere experiences this when it’s tilted away from the Sun
Winter is the coldest season, with shorter daylight hours and less direct sunlight.
Year
The time it takes a planet to orbit once around the Sun
Earth takes 365.25 days to orbit the Sun but a calendar year is 365 days.
