Lecture Notes: Earth's Atmosphere and the Moon's Temperature

Key Differences Between Earth and Moon

• Temperature Variations:
  • Moon: Average temperature -18°C
  • Temperature range on Moon: -170°C (night) to 100°C (noon)
  • Earth's temperature range is much more moderate.

Earth’s Atmosphere

• Functions:
  • Acts as a shield against the sun’s harmful rays.
  • Reflects one-third of less-intense visible light.
  • Traps infrared radiation (heat) to prevent freezing at night.

Radiation Absorption

• Requirements:
  • Atmosphere needs electrically charged particles to absorb radiation.
• Gas Molecules:
  • Most are neutral, balanced in protons and electrons.
  • Some are lopsided enabling them to absorb infrared rays (e.g., water, ozone, nitrous oxide).

Role of Greenhouse Gases

• Carbon Dioxide and Methane:
  • Not initially lopsided but become so through motion and collisions.
  • Absorb infrared rays, contributing to heat insulation of Earth.

Atmospheric Composition

• Majority of Atmosphere:
  • Composed of nitrogen and oxygen which do not absorb infrared radiation due to symmetry.
  • Only 1% is lopsided but effectively intercepts 90% of outgoing heat.

Importance of Radiation Pinball

• Climate Impact:
  • Historical data shows small changes in atmospheric CO2 lead to significant temperature changes.
  • Current atmospheric conditions are more challenging compared to the past 800,000 years.

Acknowledgments

• Kurzgesagt Collaboration: Appreciation for animation work.
• Supporters: Mention of support platforms like Subbable.com now merged with Patreon.com.