Planetary OrbitSpace Objects

By: Brittany D. Alexander

Out of a huge cloud of different gases and

specks of dust!

How was our solar system formed?

Solar System Formation

The cloud flattened into a disk of swirling material.

o Most of the mass was drew to the center- star

tiny bits of dust and frozen gases stuck together into clumps

o Large clumps became planets.

Objects move in the same direction that the flat disk was turning

Gravity is a pull between all objects in the universe. This is influenced by the mass of the

objects and the distance between them.

A more massive object (sun) has a greater pull on the less massive

object. (planets)

Gravitation forces are influenced by mass and

distance

The closer the distance between the objects the greater the pull.

These two factors (mass and distance) have numerous applications on motions of celestial bodies.

- The moon has a greater effect on the Earth’s tides than the Sun because it is closer to Earth.

1. Why does the Sun’s gravity not pull Earth’s moon into orbit around itself?

2. Which moon has the greatest gravitational pull on Planet “X’?

3. If the meteoroid moved directly between Planet X and Planet Y, what would be the result?

Effects of Gravity on Planetary Orbits

The sun’s gravitational attraction, along with the forward motion of the planets, keeps the planets moving in an elliptical orbit and determines how fast they go.

Planets closer to the sun orbit faster than planets farther from the Sun because the gravitational attraction ins greater.

When the planets are further away, the planets orbit slower because of the decreased attraction between them.

Solar System Formation

Astronomers divide the solar system into the inner planets and outer planets.

Not all the clumps from the nebula grew big enough to be called planets

- asteroids, comets, meteors, meteoroids, meteorites.

Asteroids

• similar to rocks or mountains

Comets• Like giant snowballs or

icebergs.

Shapes•You can tell a little bit about the size of an object in space from its shape.

•An object with enough mass becomes strong enough to make the object round. Everything is pulled towards the center.

• As space objects form, gravity pulls the clumps together to form an uneven shape. The pieces pull each other closer.

• Lumpy objects are usually much smaller than round objects

More on Inner and Outer Planets TOMORROW!

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