Goldilocks Earth

After 700 million years the meteor bombardments that created the Earth slowed down. The Moon was originally a lot closer to Earth. (It is still moving away.)

The Earth’s tilt moderates the temperature across the whole planet. The tilt is held stable due to the exceptionally large moon.

The combination of land and and sea allows the carbon cycle to regulate the planet’s temperature.

Without a biological ecosystem, free oxygen would disappear: oxidizing surface materials or forming nitric acid.

Free oxygen on Earth forms ozone. Which protects animals from from UV radiation.

Water is the 3rd most plentiful material in the universe. It came to Earth in meteorites and comets. (Back to the first line.)

(From The Life And Death of Planet Earth. Peter Ward & Donald Brownlee.)

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s