Astronomy: Solar System and Sun Basics

Solar System Planets

• Our solar system has 8 planets: 4 inner planets (Mercury, Venus, Earth, Mars) and 4 outer planets (Jupiter, Saturn, Uranus, Neptune).
• Inner planets are terrestrial (rocky) with few or no moons.
• Outer planets are either gas giants (Jupiter, Saturn) or ice giants (Uranus, Neptune). Gas giants have many moons and rings. Ice giants also have moons and (sometimes visible) rings.

Sun's Structure and Activity

• Sun's Interior:
• Core: Central region
• Radiative zone: Energy transfer via radiation
• Convective zone: Energy transfer via convection
• Sun's Surface and Atmosphere:
• Photosphere: Visible surface
• Chromosphere: Sun's atmosphere
• Corona: Outermost atmosphere
• Sun Features:
• Sunspots: Cooler areas on the photosphere
• Solar flares: Sudden bursts of energy
• Solar prominences: Streams of glowing gas

Big Bang Theory

• The Big Bang Theory explains the universe's origin.
• About 14 billion years ago, the universe began as a giant explosion.
• This expansion and cooling led to the formation of matter, stars, and galaxies.

Artificial Satellites

• Artificial satellites are used for various applications:
• Weather forecasting
• Navigation (e.g., GPS)
• Exploring the universe

Sustainability and Human Impact

• Human activities significantly affect ecosystem sustainability.
• These activities alter both biotic and abiotic factors of ecosystems.
• Examples of human activities that change sustainability: Species diversity loss, Agriculture, Deforestation, Fossil fuel usage.
• Biodiversity is variety of life in an ecosystem, high biodiversity means greater stability.

Photosynthesis and Cellular Respiration

• Photosynthesis:
• Producers (like plants) use light energy to convert carbon dioxide and water into glucose (sugar) and oxygen.
• Occurs in chloroplasts
• Cellular Respiration:
• Consumers use oxygen and glucose stored in food to release energy.
• Produces carbon dioxide and water as waste products.
• Occurs in mitochondria
• Both processes are complementary: The reactants of one are the products of the other.

Carbon Footprint

• A carbon footprint is the total greenhouse gases emitted from human activities.
• Increased carbon dioxide leads to global warming, climate change, ocean acidification, and sea-level rise.

Water Cycle

• The water cycle involves evaporation, condensation, precipitation, and runoff.
• Plants also contribute to the cycle through transpiration.

Water Cycle and Human Activities

• Irrigation, hydroelectricity, deforestation, and fossil fuels alter the water cycle in different ways.
• Irrigation removes water from natural sources, changing evaporation and rainfall patterns.
• Dams for hydroelectricity alter river function and water levels.
• Deforestation reduces transpiration, potentially lowering water levels in the atmosphere
• Fossil fuels impact the water cycle through climate change, increasing evaporation and ice melt.