So far as we know, Earth is the only planet in our solar system that supports life. Describe/explain four major factors/characteristics unique to Earth, allowing for the evolution and support of life

Question

What will be an ideal response?

Answer 1

The presence of water is often cited as the first critical factor, as all life we are familiar with requires water to live. The presence of water in a liquid state, especially in Earth's vast oceans, plays a central role in maintaining temperatures that support life, as these large liquid reservoirs help to moderate any extreme temperature fluctuations. Water vapor in the atmosphere also influences the extent of evaporation and precipitation, allowing water to cycle across the planet's surface.
A second critical factor is our unique distance from the sun (93 million miles). At this distance, the sun's energy and resulting temperature are not extreme, allowing organic compounds to form and life to flourish. A third critical factor was the evolution of photosynthetic organisms, which ultimately decreased the original concentrations of carbon dioxide and increased oxygen concentrations in the atmosphere, allowing a great diversity of life to evolve over the past 3.8 billion years. A fourth unique factor is the magnetic field arising from convection currents in the Earth's core and the Earth's rotation. This magnetic field deflects the lethal ionizing radiation from solar winds, to which other planets in our solar system are regularly subjected.