Where Did Earth's Water Come From?

Percival Lowell, a wealthy American businessman, studied Mars in 1909 and believed that the canals he observed were evidence of intelligent Martians trying to survive on a drying planet.

Mariner missions in the 1960s debunked Lowell's theories by revealing a barren, waterless Mars.

Earth, on the other hand, is a water-rich planet with oceans, rivers, lakes, and ice.

The origins of Earth's water are traced back to rocky asteroids from the outer solar system that collided with Earth, delivering water and precious metals like gold.

The water cycle on Earth involves evaporation, condensation, precipitation, and the formation of rivers, lakes, and oceans.

Earth's climate has fluctuated over its history, from ice-covered periods to steamy tropical climates, influenced by factors like the Sun's intensity and the composition of the atmosphere.

Earth's magnetic field protects the atmosphere and water from the solar wind, unlike Mars, which lost its water due to its smaller size and lack of a magnetic field.

The video ends with a teaser for the next episode on plate tectonics and the origins of life on Earth.

Researchers or sources featured

• Percival Lowell
• NASA Mariner missions
• Apollo 17 astronauts