Roughly 4.6 billion years ago, the Sun was born from the gas and dust of a nebula that underwent gravitational collapse. The remaining gas and dust settled into a protoplanetary disk that slowly accreted to form the planets, including Earth. About 4.5 billion years ago, our planet was impacted by a Mars-sized body (Theia), which led to the formation of the Moon. According to current theories, water was introduced to Earth and the inner planets by asteroids and comets that permeated the early Solar System.
The timing of this event is of major importance since the introduction of water was key to the origin of life on Earth. Exactly when this event occurred has been a mystery for some time, but astronomers generally thought it had arrived early during Earth’s formation. According to a recent study by a team led by scientists from the University of Rutgers-New Brunswick, water may have arrived near “late accretion” – the final stages of Earth’s formation. These findings could seriously affect our understanding of when life first emerged on Earth.
Continue reading “Water Arrived in the Final Stages of Earth's Formation”