The Solar System & Universe 1
What distance measurement do scientists use to measure distances within the solar system?
Astronomical Units
What happens in a heliocentric solar system?
The planets orbit around a star at the center of the solar system.
What galaxy do we live in?
Milky Way
Newton’s 1st Law – meaning?
Newton’s 2nd Law – meaning?
Newton’s 3rd Law – meaning?
Law of Inertia
Force = Mass × Acceleration
Action & Reaction
What unit of measurement would you use to measure the Sun to Rigel?
Light Years
How did our solar system form?
From rocks being attracted to the sun's gravity, which then accumulated into planets.
What is a geocentric soar system?
A solar system with Earth at the center.
Why do we measure distance in light-years?
We measure distance in light-years because the universe is so incredibly large that using everyday units like kilometers or miles becomes impractical.
If a planet gets closer to a star, what happens to speed?
If a planet gets closer to a star, its orbital speed increases.
Because the star’s gravitational pull becomes stronger at a shorter distance.
A stronger pull forces the planet to move faster to stay in orbit instead of falling inward.
What is the universe made of?
Billions of solar systems, stars, and galaxies
What is the difference between terrestrial planets and gaseous planets?
Terrestrial planets are made of rock and gaseous planets are made of gas.
Why are planets closer to the Sun hotter?
They receive more direct solar radiation.
The Sun is the main source of heat in the Solar System, and the closer a planet is to it, the more energy and heat it absorbs.
Mercury & Venus → very hot (close to the Sun)
Uranus & Neptune → extremely cold (far from the Sun)
What force pulls gas & dust into galaxies?
Gravity
Action-reaction pair example for space?
An action–reaction example in space is how rockets move.
🚀 Example:
Action: Hot gases shoot downward out of the rocket engine.
Reaction: The rocket is pushed upward in the opposite direction.
This works even without air, which is why rockets can travel in space.
Which planet would have the highest surface temperature?
Venus
What phrase do we use to memorize the planets in order from the Sun?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
My Very Educated Mother Just Served Us Noodles
Why do planets farther from the Sun orbit more slowly?
Planets farther from the Sun orbit more slowly because the Sun’s gravitational pull is weaker at greater distances.
When a planet is close to the Sun, the strong gravitational pull forces it to move faster to stay in orbit.
Name two galaxy shapes.
Spiral Galaxy (like the Milky Way)
Elliptical Galaxy
What happens if gravity suddenly disappears?
If gravity suddenly disappeared, everything in the universe would stop being held together.
You, animals, cars — everything would float away.
The air and oceans would drift into space.
galaxies would fall apart and stars would drift away forever.
Does the sun rotate?
No, the Earth rotates around the sun
Which planet would have the strongest gravitational pull if mass is the only factor?
Jupiter is the most massive planet in our Solar System, so it would have the strongest gravitational pull when mass is the only factor.
1.90 × 10²⁷ kg
Which planet has the fastest orbital velocity and why?
Mercury has the fastest orbital velocity.
Mercury is the closest planet to the Sun, so it experiences the strongest gravitational pull.
To avoid being pulled into the Sun, it must travel very quickly along its orbit.
What causes galaxies to change shape over time?
Galaxies change shape over time mainly because of gravity and movement in space.
Why does a small mass accelerate more near a large planet?
A small mass accelerates more near a large planet because gravity pulls it strongly, and it has less inertia to resist that pull.
Think about the theories scientists have developed regarding the formaion of the solar system. Determine similarities and differences in the way the sun and the planets formed.
The nebular hypothesis — the idea that the Solar System formed from a giant cloud of gas and dust called a solar nebula.