Solar System
This planet is closest to the Sun and is the smallest in our solar system.
Mercury.
The glowing ball of gas at the center of our solar system that provides light and heat.
The Sun.
The Moon phase when we see the entire lit side from Earth.
Full Moon.
This vehicle carries astronauts to and from space; it starts on a launch pad and travels into orbit.
Rocket/ Spacecraft.
The force that pulls objects toward Earth and keeps planets in orbit around the Sun.
Gravity.
The largest planet in our solar system, known for its Great Red Spot.
Jupiter.
A system of billions of stars, dust, and gas held together by gravity; we live in the ________ Galaxy.
Milky Way.
When Earth’s shadow falls on the Moon, this event occurs.
A lunar eclipse.
The tool astronauts use to breathe and survive in the vacuum of space when outside a spacecraft.
Space suit.
The path an object takes around another object because of gravity.
Orbit.
Name the planet that has a prominent ring system visible from Earth with a small telescope.
Saturn.
A star’s color tells us about its temperature. Which color indicates a hotter star: red or blue?
Blue.
Explain why we have day and night on Earth. (Single clear sentence.)
Earth spins on its axis; the side facing the Sun has day, the side away has night.
Name one benefit of space satellites for life on Earth (e.g., communications, weather forecasting).
Examples: communication satellites enable phone/Internet; weather satellites help forecast storms; GPS satellites help navigation.
State Newton’s First Law of Motion in a simple sentence.
An object at rest stays at rest, and an object in motion stays in motion unless acted on by an outside force.
This zone in our solar system, beyond Neptune, contains many icy bodies and dwarf planets including Pluto.
The Kuiper Belt.
The life cycle stage when a medium-sized star like the Sun expands and becomes very large and bright near the end of its life.
Red Giant.
During which moon phase is a solar eclipse possible?
New Moon.
Explain what a space probe is and give one example (robotic; no humans onboard).
A space probe is an unmanned spacecraft sent to study objects in space
Light travels in straight lines except when it bends crossing different materials. This bending is called what?
Refraction.
Explain why inner (terrestrial) planets and outer (gas giant) planets differ in composition.
Inner planets are rocky and denser because they formed where it was too warm for gases and ices to stay; outer planets formed farther out where ices could remain and they accumulated thick gas envelopes.
Define a light-year and explain why astronomers use this unit.
A light-year is the distance light travels in one year (about 9.46 trillion kilometers); astronomers use it because space distances are incredibly large and easier to express in terms of the speed of light.
Describe how the tilt of Earth's axis affects seasons.
Earth's axis is tilted relative to its orbit around the Sun, so during different parts of the orbit, either the Northern or Southern Hemisphere gets more direct sunlight, causing seasons.
Describe how telescopes placed in space (like the Hubble Space Telescope) give clearer images than ground telescopes.
Space telescopes are above Earth’s atmosphere, so there is no atmospheric blurring or absorption; they collect clearer, sharper light across more wavelengths.
Explain gravity’s role in forming the solar system from a rotating cloud of gas and dust.
Gravity pulled together particles in the spinning cloud, causing the cloud to collapse and form the Sun at the center while leftover material formed planets; gravity continued to pull matter together to grow planets and clear their orbits.