Earth's Early History and the Late Heavy Bombardment

What was the primary composition of Earth's initial atmosphere?

• Oxygen and nitrogen

• Hydrogen and helium

• Carbon dioxide and methane

• Sulfur dioxide and ammonia

What event led to the formation of the Moon?

• A massive solar flare

• Volcanic activity on Earth

• The accretion of solar nebula

• A collision with a Mars-sized object

What evidence suggests that Earth's surface cooled quickly after the Moon's formation?

• The presence of large continents

• The discovery of zircon crystals

• The abundance of volcanic rocks

• The presence of iron-rich meteorites

By 4.2 billion years ago, what was the state of Earth's continents?

• Large continents had formed

• Only small island continents existed

• Continents were covered in ice

• Continents were submerged underwater

What is the Late Heavy Bombardment?

• A dramatic increase in comet and asteroid impacts

• A period of intense volcanic activity

• The cooling of Earth's core

• The formation of Earth's magnetic field

How do scientists know about the Late Heavy Bombardment?

• Through computer simulations of the solar system

• By analyzing meteorites found on Earth

• Through lunar samples returned by Apollo missions

• By studying Earth's surface craters

What hypothesis explains the cause of the Late Heavy Bombardment?

• A sudden increase in solar activity

• Changes in the orbits of outer planets

• A collision with a rogue planet

• The formation of a new asteroid belt

What effect did the orbital changes of Neptune have on the solar system?

• It increased volcanic activity on Earth

• It scattered Kuiper belt objects

• It caused the Sun to expand

• It led to the formation of new planets

What was the result of the Late Heavy Bombardment on Earth's surface?

• The formation of large mountain ranges

• The extinction of early life forms

• The boiling of Earth's oceans

• The creation of a new atmosphere

What is the significance of the zircon crystals found in Jack Hills, Australia?

• They reveal the composition of Earth's core

• They provide evidence of early ocean formation

• They indicate the presence of early life

• They show the age of the Moon