Astronomy Science

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Astronomer

Astronomer

• A scientist who studies planets, stars, and the solar system.

Axis

• An imaginary straight line joining the north and south poles of the Earth.

Equinox

• A day on which day and night are the same length.

Orbit

• The path a planet moves around the sun/ star, or a moon moves around a planet.

Partial eclipse

• When only some of the Sun’s light is blocked by the moon.

Phases of the Moon

• A change in the shape of the Moon visible to the Earth.

Solar energy

• Solar energy is made from energy making atoms by colliding with each other in the centre of the Sun.

Solar system

• It’s made up of the sun and all the planets, dwarf planets, moons and asteroids that travel around the sun or each other.

Telescope

• An optical instrument that uses lenses and mirrors to make distant objects appear closer and larger.

Total solar eclipse

• When the Moon blocks the maximum amount of light from the sun.

Artificial 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.

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.

Milky Way galaxy

• 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

• 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.

Solar 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 quarter 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.

Waning Moon

• 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.

What is a summer solstice

• A summer solstice is when the Earth's tilt is most inclined towards the sun, resulting in the longest day and shortest night of the year.

• It happens around June 20th or 21st in the Northern hemisphere and around December 21st or 22nd in the Southern hemisphere.

What is an autumn equinox

• An autumn equinox occurs twice a year, usually on September 22 or 23 in the Northern Hemisphere, and March 20 or 21.

• It signals the start of autumn and has equal day and night lengths. The sun is directly above the Earth's equator during this time, creating a balance between daylight and darkness.

Order of the phases of the moon

The order of the phases of the moon is as follows:

1. New Moon: The moon is not visible from Earth as it is positioned between the Earth and the Sun.

2. Waxing Crescent: A small sliver of the moon becomes visible on the right side.

3. First Quarter: Half of the moon is visible, resembling a half-circle shape.

4. Waxing Gibbous: More than half of the moon is visible, but it is not yet a full moon.

5. Full Moon: The entire face of the moon is visible from Earth.

6. Waning Gibbous: More than half of the moon is visible, but it is starting to decrease in size.

7. Third Quarter: Half of the moon is visible, resembling a half-circle shape, but on the left side.

8. Waning Crescent: A small sliver of the moon becomes visible on the left side.

9. New Moon: The moon is not visible from Earth as it is positioned between the Earth and the Sun, starting the cycle again.

This cycle repeats approximately every 29.5 days.

What each phase of the moon looks like

The phases of the moon include:

1. New Moon: The moon is not visible from Earth.

2. Waxing Crescent: A small sliver of the moon is visible, growing larger each night.

3. First Quarter: Half of the moon is visible, resembling a half-circle.

4. Waxing Gibbous: More than half of the moon is visible, but not fully illuminated.

5. Full Moon: The entire face of the moon is visible and appears as a complete circle.

6. Waning Gibbous: More than half of the moon is visible, but not fully illuminated.

7. Third Quarter: Half of the moon is visible, resembling a half-circle.

8. Waning Crescent: A small sliver of the moon is visible, shrinking each night.

What is a lunar eclipse

• When the Moon is in the Earth’s shadow and appears dark.

• It appears a reddish - orange colour.

• The three types of lunar eclipses are total, partial, and penumbral.

What is happening to the moon and sun during a lunar eclipse

• The Earth comes between the Sun and the Moon, causing the Moon to move into the Earth's shadow. The Sun's light is blocked by the Earth, resulting in the Moon appearing dark or reddish in colour.

What is a solar eclipse

• It occurs when the Moon passes between the Sun and the Earth, blocking the sunlight and casting a shadow on the Earth's surface.

• The sun’s light is mostly blocked.

• It is influenced by the alignment of the Sun, Moon, and Earth, as well as the distance between them.

What is happening to the moon and sun during a solar eclipse

• The moon passes between the sun and the Earth, blocking the sunlight and casting a shadow on the Earth's surface. The moon appears to cover the sun, causing a temporary decrease in brightness and creating a dark area on Earth known as the umbra. This alignment of the moon, sun, and Earth results in either a partial or total solar eclipse, depending on the observer's location.

Revolution of Earth and the sun

• The revolution of Earth around the sun is known as the Earth's orbit. It takes approximately 365.25 days for the Earth to complete one revolution around the sun, resulting in a year. This revolution is responsible for the changing seasons and the varying lengths of daylight throughout the year. The Earth's orbit is elliptical, with the sun located at one of the foci of the ellipse.

Rotation of Earth and the sun

• The rotation of the Earth takes about 24 hours and causes day and night. It also affects the Sun's apparent movement across the sky. However, the Sun doesn't rotate around the Earth. Instead, the Earth revolves around the Sun in about 365.25 days, causing the change of seasons.

Why does it take planets different times to go around the sun

• Different planets take different times to orbit because they are at different lengths to the sun.

Time taken for a revolution of the Earth

• The time taken for a revolution of the Earth around the Sun is approximately 365.25 days.

Telescopes

• A telescope is a piece of equipment that has a magnified lens to look at objects that are extremely far away, namely space objects, such as planets.

• Telescopes use curved mirrors to gather light from the sky.

Does the moon create its own light

• No, the moon does not create its own light. It reflects sunlight, which is why we see it shining in the night sky.

Why do seasons occur?

The Earth’s spin axis is tilted with respect to its orbital plane.