Solar System Formation

Midterm

Nebular Theory

The theory that the solar system formed from a large cloud of gas and dust called a nebula.

Interstellar Cloud (Nebula)

A cloud of dust, hydrogen, and helium in space.

Collapse of Nebula

Gravity pulls matter together, causing the cloud to collapse.

Spinning Collapsed Cloud

As the cloud collapses, it spins faster and the center becomes the Sun.

Nuclear Fusion Begins

When temperatures reach about 15 million degrees Celsius, fusion starts in the Sun.

Formation of Solar System Disk

The cloud flattens into a rotating disk that becomes the solar system.

Planet Classification by Distance

Planets are classified as inner or outer based on distance from the Sun.

Inner Planets

Mercury, Venus, Earth, and Mars.

Outer Planets

Jupiter, Saturn, Uranus, and Neptune.

Ellipse

An oval-shaped path that planets follow in their orbits.

Eccentricity

A measure of how stretched or circular an orbit is.

Low Eccentricity

An orbit that is nearly circular.

High Eccentricity

An orbit that is more elongated.

Gravity

The force of attraction between two objects.

Factors Affecting Gravity

The masses of the objects and the distance between them.

Newton’s Law of Universal Gravitation

Every object attracts every other object based on mass and distance.

Kepler’s First Law of Planetary Motion

Each planet orbits the Sun in an elliptical shape.

Kepler’s Second Law of Planetary Motion

A planet sweeps out equal areas in equal amounts of time.

Orbital Speed of Planets

Planets move faster when closer to the Sun and slower when farther away.

Kepler’s Third Law of Planetary Motion

The relationship between orbital period and orbit size is p² = a³.

Meaning of Kepler’s Third Law

The larger a planet’s orbit, the longer it takes to complete one revolution around the Sun.