since Earth is exposed to solar radiation, why doesn't Earth have the same temperature as the Sun?

The Sun, an immense powerhouse of energy, bombards our planet with solar radiation continually. But have you ever wondered why Earth maintains its comfortable temperature instead of matching the scorching heat of the Sun? It all comes down to a cosmic balancing act.

The Earth orbits at a safe distance of about 93 million miles (approximately 150 million kilometers) away from the Sun. This vast space allows for a significant drop in the intensity of solar radiation as it travels across the vacuum of space. This phenomenon adheres to the inverse square law, which tells us that as the distance from a source of radiation increases, the intensity of that radiation diminishes proportionally to the square of the distance. Consequently, by the time solar radiation reaches Earth, its strength is diluted enough to warm our planet without turning it into an inferno.

The Earth's atmosphere, a mixture of various gases enveloping our planet, plays the role of a gatekeeper to solar radiation. It absorbs, reflects, and scatters sunlight in ways that greatly affect the climate and temperature on Earth.

For instance, about 30% of the incoming solar radiation is reflected back into space by clouds, atmospheric particles, and bright ground surfaces like ice caps. This reflection helps prevent excessive heating. Furthermore, gases in the atmosphere such as water vapor, carbon dioxide, and methane absorb heat, functioning mainly in the infrared spectrum. This absorption not only warms our atmosphere but also contributes to the greenhouse effect. The atmosphere filters out harmful ultraviolet and other high-energy radiation, safeguarding life on the surface. Without this atmospheric modulation of solar radiation, Earth's climate would be drastically different and less conducive to sustaining life as we know it.

Understanding the Earth’s thermal balance is vital. It's a delicate process of heat absorption and dissipation that keeps the planet from overheating or becoming too cold.

When solar radiation reaches the Earth's surface, several things can happen. A portion of this radiation is absorbed, particularly by darker surfaces, which then warm up. This increase in temperature causes the Earth to emit infrared radiation. Oceans and forests also play a significant role, absorbing and storing heat, thereby regulating the climate. However, just as the Earth absorbs solar radiation, it also dissipates heat back into space. This ongoing interaction ensures that the planet's temperature remains within a range that supports the diverse ecosystems present. The balance between how much energy is absorbed from the sun and how much is emitted back into space is what keeps Earth's average temperature relatively stable over time.