The Solar SystemWe are spending this unit learning more about the solar system that our

little planet is in. Use this presentation to get caught up on your Solar System Portfolio – due Tuesday November 10th.

Early Models of the Solar System

There were two models of the solar system: geocentric and heliocentric. “geo-” means Earth “helio-” means Sun “-centric” means centered

The information on the next slide is for the two door foldable. Lift up each flap and write the information inside.

Geocentric Definition - Earth is at the center of

the solar system being orbited by the Sun and other planets

(sketch a picture of a geocentric solar system)

Scientists Aristotle - believed that if Earth were

moving, then the stars would move

Ptolemy - planets move at constant speeds in perfect circles around Earth

Heliocentric Definition – Earth and other planets

orbit the Sun (sketch a picture of a heliocentric solar

system) Scientists

Aristarchus – tried to measure the relative distances between Earth, the moon, and the Sun

Copernicus – developed the 1st detailed heliocentric model

Galileo – saw the phases of Venus and 4 of Jupiter’s moons

Early Models of the Solar System

Newton’s Law of Universal Gravitation

Isaac Newton determined the relationship between mass, distance, and gravity.

The information on the next slide is for the door foldable. Write the “Mass” notes on the left side and the “Distance” notes on the right side.

MASS Larger objects have a

stronger gravitational force.

The Sun is the largest object in the solar system, so it has the greatest gravitational pull.

DISTANCE The closer together two

objects are, the stronger the gravitational force.

The moon is closer to Earth, so we can see the effect of its gravitational pull.

Newton’s Law of Universal Gravitation

Rotation vs. RevolutionThese are two terms that often get used interchangeably, but they mean

two different things. These notes are on the far right panel of your portfolio!

Rotation Refers to a planet

spinning on its axis. One day = one

rotation of the planet Earth takes about 24

hours to rotate once on its axis.

Revolution Refers to a planet

orbiting around the Sun. One year = one

revolution of the planet Earth takes about 365

days to rotate once on its axis.

Kepler’s Laws of Planetary Motion

Johannes Kepler explained how planets move in their orbits around the Sun.

The information on the next slides are for the three door foldable. Lift each door and record the notes about Kepler’s Laws.

Kepler’s 1st Law The Law of Orbits Planets orbit the

Sun in an ellipse with the Sun at one focus.

Kepler’s Laws of Planetary Motion

Kepler’s 2nd Law The Law of Areas Planets cover equal

areas in equal time. A planet will move

faster in its orbit when it’s closer to the Sun and slower when it’s farther away.

Kepler’s Laws of Planetary Motion

Kepler’s 3rd Law The Law of Periods Planets closer to

the Sun will complete an orbit faster than planets farther away.

Kepler’s Laws of Planetary Motion

Planets in our Solar System

As we go through the presentation, take notes on your note sheet! Write neatly.

There are two types of planets: terrestrial and gas giant planets.

Terrestrial Planets Inner planets, formed close to the Sun.

Solid surfaces Thin atmospheres Small and dense

Gas Giant Planets Outer planets, formed farther from the Sun.

Solid core Thick, icy atmosphere Large, low-density Many moons

Mercury Mercury is the smallest

planet in our solar system and closest to the Sun.

One day = 58 Earth days One year = 88 Earth days 0 moons It has almost no

atmosphere because the solar winds blow it away!

Venus Venus is known as Earth’s

“evil twin” because it’s about the same size, but toxic!

One day = 243 Earth days One year = 225 Earth days 0 moons The atmosphere is almost

97% CO2 and it rains sulfuric acid.

Earth Home sweet home! Earth is

at the perfect distance from the Sun. We get warm, but not too warm…

One day = 24 Earth hours One year = 365 Earth days 1 moon The atmosphere is mainly

nitrogen and oxygen.

Mars The red planet. Although

smaller than Earth, Mars was a lot like our planet before solar activity stripped the atmosphere.

One day = 24 Earth hours One year = 1.88 Earth years 2 moons The atmosphere is about 95%

CO2 and 2.7% nitrogen.

Some scientists think that we could “terraform” Mars and make it habitable like

Earth!

Pack your bags!

The largest planet located just beyond the asteroid belt…

One day = 10 Earth hours One year = 11.86 Earth years 63 known moons The atmosphere is icy. Mainly

hydrogen and helium. The stripes are bands of wind!

Jupiter

Famous for its prominent rings and has beautiful auroras.

One day = 10.5 Earth hours One year = 29.5 Earth years 60 moons The atmosphere is cold and

mainly hydrogen and helium. The pressures are so great that it rains diamonds on Saturn!

Saturn

This gas giant is on its side. So it rolls around the Sun instead of spinning.

One day = 17.5 Earth hours One year = 84 Earth years 27 moons The atmosphere is mainly

hydrogen and helium, but the methane gives it a blue appearance.

Uranus

This gas giant is the farthest planet from the Sun. It has rings made of rocks and gravel.

One day = 16 Earth hours One year = 164.8 Earth years 13 moons The atmosphere is hydrogen,

helium, and methane. It’s the farthest planet from the Sun, so it has more ices.

Neptune

The Sun The Sun contains 99% of the entire mass

of the solar system. The only star in our solar system. Provides heat and light; partially

responsible for life on Earth.

Small Bodies in the Solar System

Asteroids Most are in the asteroid belt between Mars and Jupiter Some cross orbits with Earth’s orbits.

Comets Ice, rock, and dust Can take 1000s of years to orbit the Sun

Meteors Small, rocky bodies Most burn up in our atmosphere and are called shooting stars