Earth's Early History

How long ago did the creation of the solar system begin?

• 4.6 million years ago

• 13 billion years ago

• 13 trillion years ago

• 4.6 billion years ago

The hot particles at the center of the nebula eventually created what?

• Proto- Planets

• Asteroids

• Proto-Star

• Jovian Planets

Accretion is...

• a process that is caused by the ongoing changes to earth's surface by volcanism and plate tectonics.

• a process driven by gravity from the sun that causes planetesimals to collide and create planets

• a process driven by an exploding supernova that causes everything to expand

• a process that is driven by inertia that creates protoplanets

Put in order the formation of the solar system.

• 1. Protostar 2. Gravitational Collapse 3. Accretion Disk 4. Planets form. 5. Solar Nebula

• 1. Nebula 2. Gravitational Collapse 3. Protostar. 4. Accretion of planetesimals 5. Creation of Planets

• 1. Nebula 2. Protoplanets 3. Gas and Dust explode 4. Creation of the Sun 5. Planets form

• 1. Protostar 2. Planetesimals 3. Accretion Disk 4. Gravitational Collapse 5. Nebula

True or False: Everything has gravitational pull

• True

• False

Why can't scientists find evidence of rocks 4.5 billion years old on earth?

• Earth's plate tectonics, volcanoes and weathering/erosion have destroyed any evidence

• The earth's atmosphere has protected us from any meteors that could have landed on earth

• Radioactive decay processes have shown rocks that are over 4.6 billion years on earth

• Venus and Mercy have meteors that have evidence that earth is 4.5 billion years old

What is a nebula?

• a region of space with no light

• it sucks in a lot of energy and creates heat

• it is at the center of the solar system

• a cloud of gas and dust where stars are born

Why do we use the moon to tell us how old the earth is?

• We use evidence from Mercury, Venus and Mars to tell the age of the earth.

• The moon has gone through heavy bombardment and earth's surface has not

• Earth's surface has been destroyed by plate tectonics and volcanoes, while the moon's surface doesn't have plate tectonics, volcanoes or erosion.

• We use asteroids from outer space to tell the age of the earth.

Why is the solar nebula theory important to telling us how old the earth is?

• Because it tells us the material in the solar system is the same as earth. So we can date the material to tell us the age of the earth.

• Because it tells us the process in which the Sun, asteroids, planets and moons were created. This gives us a clearer picture of the solar system.

• Because it can tell us how old the solar system is.

• Because we need to know the history of the earth to understand its future.

What role does gravity play in accretion?

• It causes the surface of the earth to be constantly destroyed and created

• It causes the asteroid belt to spread apart and float in space

• It causes objects to spin very quickly causing objects to move toward each other more.

• As planetesimals get bigger, they attract more objects to collide with it.