Earth's Early Atmosphere Flashcards

All 7 cards in this deck

According to one theory, which gas made up most of Earth's early atmosphere?

Carbon dioxide, with little or no oxygen gas.

What produced the gases that formed Earth's early atmosphere?

Intense volcanic activity during the first billion years of Earth's existence.

Which two planets have atmospheres today that may be like Earth's early atmosphere?

Mars and Venus (mainly carbon dioxide).

Which two gases may have been present in small proportions in Earth's early atmosphere?

Methane and ammonia.

Where did the nitrogen in the atmosphere come from, and how did its percentage change?

It was produced by volcanoes and gradually built up in the atmosphere.

True or false? Scientists know for certain what was in Earth's early atmosphere.

False. Evidence is limited because of the 4.6 billion year time scale, so theories have changed and developed over time.

True or false? Evidence for what was in the Earth's early atmosphere is limited because of the time scale of 4.6 billion years.

True. Because so little evidence survives, theories about the early atmosphere have changed and developed over time.