How the Oceans Formed

The video explains the origins of Earth's water, starting with its absence 4.5 billion years ago when Earth was too hot for liquid water. Water vapor formed inside the Earth and was released by volcanic eruptions. As the planet cooled, rain formed the first oceans. However, only half of Earth's water came from this process; the rest was delivered by comets. NASA's 2005 comet mission revealed the significant water content in comets, supporting the theory that they contributed to Earth's water supply. The water in today's oceans is the same that existed billions of years ago.

What was the state of Earth 4.5 billion years ago?

• A frozen wasteland

• A molten inferno

• A lush green planet

• A desert with no atmosphere

How did the first oceans on Earth form?

• From melting glaciers

• Through continuous rainfall over thousands of years

• From underground springs

• By the collision of tectonic plates

What percentage of Earth's water is believed to have come from outer space?

• 75%

• 10%

• 25%

• 50%

What did NASA discover about comets in 2005?

• They are responsible for Earth's atmosphere

• They are made entirely of ice

• They contain large amounts of water

• They have no water at all

What is the significance of comets in Earth's history?

• They created Earth's magnetic field

• They contributed significantly to Earth's water supply

• They provided essential minerals for life

• They caused mass extinctions