IB Biology A1.1 Definitions
This page contains our IB Biology definitions for A1.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Origin of water'.
Asteroid Theory
The hypothesis that Earth's water was delivered by water-rich asteroids that collided with the Earth during the early stages of its formation
evaporation
A liquid absorbing heat to turn into a gas. Evaporation can occur randomly from a liquid's surface. Synonym for boiling and vaporization.
Gas Giants
Large planets composed mostly of gases such as hydrogen and helium, found in the outer parts of the Solar System (e.g., Jupiter, Saturn, Uranus, Neptune)
Goldilocks Zone
The region around a star where conditions are just right for liquid water to exist on a planet's surface, potentially allowing for life
Protoplanetary Disc
A rotating circumstellar disc of dense gas and dust surrounding a young newly formed star, from which planets are formed
Protostar
A young star still in the process of forming, gathering mass from its parent molecular cloud.
Solar Winds
Streams of charged particles released from the upper atmosphere of the Sun, which can influence planetary atmospheres and magnetic fields
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