Wednesday, April 11, 2007

What Was Early Earth Like?

The planet is about 4.5 billion years old. It was very hot. Within just a few million years – say 4.3 billion years ago, it had cooled to about where it is today. That is Earth had a landscape that would roughly be familiar to us.

According to LiveScience,

Mark Harrison, a geochemist at UCLA, suggests picturing a sandy beach near sparkling blue water with a blue sky above ... and lots of volcanoes.

The full story will be in the May 6 issue of the journal Science.

Early life gave the Earth a different color. Early plants were purple, not green.

Plants today use a molecule called “chlorophyll” to take the Sun’s rays and Carbon Dioxide from the atmosphere, and convert it to Oxygen. The process is called “photosynthesis.” Chlorophyll gives plants their green color.

Early plants used retinal. This molecule made the plants purple.

Here is the story from LiveScience.