Earth Sun Moon System

Star Noun

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[star]

• A celestial body that emits light and heat due to nuclear fusion.

• A small, cold rock floating in space.

• A planet that orbits a star.

• A satellite that reflects light from a star.

What is a solstice?

• The day when a hemisphere is tilted most strongly toward or away from the sun, causing the longest or shortest day.

• A period of time when the sun is directly above the equator.

• The time of year when the sun is at its highest point in the sky.

• A day when the sun rises and sets at the same time.

Axis

• An imaginary line passing through a planet's center, from the North Pole to the South Pole, on which it rotates.

• A physical boundary that separates different regions of a planet.

• A type of celestial body that orbits a star.

• A measurement of the distance between two points on a planet.

Ellipse

• A circular shape that describes the path of a planet's orbit around the sun.

• An oval shape that describes the path of a planet's orbit around the sun in the heliocentric model.

• A straight line that represents the shortest distance between two points.

• A polygon with four equal sides and angles.

What is Gravity?

• The universal force of attraction that acts between all objects with mass, pulling them toward each other.

• A force that only affects large celestial bodies like planets and stars.

• A phenomenon that causes objects to float in space.

• The force that keeps satellites in orbit around the Earth.

What is the definition of Rotation?

• The spinning motion of a planet, moon, or other celestial body on its own axis.

• The movement of a celestial body around another body in space.

• The process of changing the position of an object in a straight line.

• The act of revolving around a central point or axis.

What is the meaning of Penumbra?

• The fully shaded inner region of a shadow cast during an eclipse.

• The partially shaded outer region of a shadow cast during an eclipse, where the light source is only partially blocked.

• The area of complete darkness during an eclipse.

• The bright light surrounding the shadow during an eclipse.

What is a planet?

• A celestial body that orbits a star, is large enough to be rounded by its own gravity, and has cleared its orbital path.

• A small rocky body that orbits a planet.

• A massive star that emits light and heat through nuclear fusion.

• A large collection of gas and dust that forms a star.

Heliocentric Model

• A model of the solar system where the sun is at the center and Earth and other planets revolve around it.

• A theory that suggests the Earth is at the center of the universe.

• A concept that describes the phases of the moon in relation to Earth.

• A model that explains the gravitational pull of the Earth on the sun.

Equinox

• The day when the sun is at its highest point in the sky.

• The day when neither hemisphere is tilted toward the sun, resulting in nearly equal lengths of day and night.

• The day when the sun is directly over the equator, causing the longest day of the year.

• The day when the seasons change from winter to spring.