And in fact, before plants appeared on Earth, scientists think there was much more carbon dioxide but no oxygen in the early atmosphere. The composition of the atmosphere has changed over time ...

Fossils Life processes can change the composition of the atmosphere. Fossils can tell scientists what living things were around at different times in Earth’s history. Evidence of early plants ...

Earth's early climate lacked oxygen, which made it impossible for many creatures to survive. How did Earth's atmosphere become oxygen-rich? What is the chemical composition of the Earth's atmosphere?

"One of the mysteries about Earth and Earth's evolution is really what was the earliest composition of ... have a way to deduce what the early Earth's atmosphere was from direct measurements ...

The puzzle is in identifying where the volatiles came from and what objects carried them to the early Earth ... 3.3 billion year old U-Xe has a composition very different from the xenon found in the ...

We are pioneering a new field of study that will use micrometeorites, grains of cosmic dust, to investigate how the composition of Earth’s atmosphere has changed over time. We will use this novel ...

In the associated video "Early Fossil Life," you can read more about these ... How did Earth's atmosphere become oxygen rich? What is the chemical composition of the Earth's atmosphere? It is composed ...