The Solar System
What keeps all planets orbiting the Sun?
Gravity.
What is a natural satellite?
An object that orbits a planet.
Does your mass change in space?
No, mass stays the same everywhere.
How long does Earth take to rotate once?
24 hours.
What causes seasons on Earth?
Earth’s 23.5° tilt and its revolution around the Sun.
How old is our Solar System?
About 4.6 billion years old.
What is the asteroid belt and where is it located?
A region of rocky objects between Mars and Jupiter.
What is weight?
The force of gravity acting on mass.
Why do we have day and night?
Earth rotates on its axis.
When the Northern Hemisphere tilts toward the Sun, what season is it?
Summer.
What are the four rocky planets?
Mercury, Venus, Earth, Mars.
What is a comet made of?
Ice, dust, and rock (“dirty snowball”).
Why do you weigh less on the Moon?
The Moon has weaker gravity.
How long does one full cycle of Moon phases take?
About 29.5 days.
Why do scientists put telescopes in space instead of on Earth?
To avoid Earth’s atmosphere, which makes images blurry.
What are the four gas giants?
Jupiter, Saturn, Uranus, Neptune.
What is the difference between a meteor and a meteorite?
Meteor = streak of light; meteorite = reaches the ground.
Which planet would you weigh the most on?
Jupiter (strongest gravity).
What is a solar eclipse?
The Moon blocks sunlight from reaching Earth.
Name two ways satellites help Earth.
Predicting weather, tracking climate, detecting illegal logging, or powering GPS.
What is the Sun made of, and why is it important?
Hot gases; it produces heat and light and keeps planets in orbit.
Why does the Moon shine?
It reflects sunlight; it does not make its own light.
Explain the relationship between a planet’s mass and its gravity.
More mass = stronger gravity; less mass = weaker gravity.
What causes the Moon’s phases?
We see different amounts of the Moon’s lit side as it orbits Earth.
What is one important job of the Canadarm2 on the ISS?
It catches cargo ships, moves equipment, or assists astronauts during spacewalks.