Galaxy, Solar System, and Space Object Basics for Students

What is a galaxy?

A huge group of stars, gas, and dust held together by gravity.

What galaxy do we live in?

We live in the Milky Way Galaxy.

What is the Solar System?

The Sun and all the objects that orbit the Sun.

What is a star?

A huge ball of hot, glowing gas that gives off light and heat.

What is a planet?

A large object in space that orbits a star.

What is a moon?

A natural object that orbits a planet.

What is an asteroid?

A rocky object that orbits the Sun.

What is a comet?

An object made mostly of ice, dust, and rock that orbits the Sun.

What is gravity?

A force that pulls objects toward each other and keeps planets and other objects in orbit.

What are the inner planets?

The four planets closest to the Sun: Mercury, Venus, Earth, and Mars.

What are the outer planets?

The four planets farthest from the Sun: Jupiter, Saturn, Uranus, and Neptune.

What are the basic components of a galaxy?

Stars, gas, and dust.

What objects are part of the Solar System?

The Sun, planets, moons, asteroids, comets, and other smaller objects.

How are stars, planets, moons, asteroids, and comets related?

They are objects in space, and gravity affects their movement and orbits.

What are the characteristics of inner planets?

They are small, rocky planets close to the Sun.

What are the characteristics of outer planets?

They are much larger and are mostly made of gases.

How do we observe objects in the Solar System?

We use telescopes, spacecraft, satellites, and other scientific instruments.

Where is Earth located in the Solar System?

Earth is the third planet from the Sun and is located in the Milky Way Galaxy.

Sun

The star at the center of our solar system

Orbit

The path an object follows as it moves around another object

Meteor

A streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere. Shooting Star

Meteorite

A meteoroid that has hit earth's surface.

Geocentric

Earth centered solar system model

Heliocentric

sun-centered model of the solar system

Gravity

A force that pulls objects toward each other; caused the formation of galaxies and stars

Big Bang

the rapid expansion of matter from a state of extremely high density and temperature marked the origin of the universe.