Joint Activity for Class 8 and 9:
Worth 10 points.
Discussion board activity involving 4-5 big picture questions.
Philosophical Questions:
Discussion on the philosophical implications of chemistry, biology, and astronomy.
Addressing questions that may not have definite answers.
Craters:
Mars has fewer craters compared to the Southern Hemisphere.
Possible explanations include craters being trapped under polar ice caps or evaporated due to climate.
There may be enough water remaining on Mars to support some conditions for life.
Size and Surface Area:
Mars is smaller compared to Earth, leading to quicker cooling in planetary terms.
Comparison of surface area vs. volume:
Surface area = 4πr²; Volume = 4/3πr³.
Larger objects have a greater surface area relative to volume.
Atmospheric Dynamics:
Atmosphere on Mars is susceptible to being stripped away by solar wind.
At the beginning of Mars's history, parts of its atmosphere may have been lost gradually.
Gravitational Potential Energy:
Significant heat source for a collapsing cloud of gas, contributing to planetary habitability.
Complexity of Habitability:
Not all planets are suitable for life; numerous factors must align for habitability.
Galileo's Discoveries of Jupiter:
Noted movements of moons around Jupiter, leading to the formulation of Kepler’s laws.
Importance of understanding orbital mechanics in astronomy.
Overview of Jupiter's Moons:
Understanding over 200 moons of Jovian planets.
Notable moons include Titan (Saturn), Io, Europa, Ganymede (Jupiter).
Significant size comparisons to Mercury.
Tidal Forces:
Moons experience strong tidal forces due to Jupiter's massive size.
Synchronous rotation: One side of the moon always faces Jupiter.
Tidal stretching leads to geological activity, affecting surface conditions.
Geological Activity:
Volcanic activity on Io due to tidal forces.
Potential for liquid water underneath icy surfaces of moons like Europa and Titan.
Conditions for Life:
Importance of internal energy sources (tidal forces and radioactive decay) for sustaining liquid water.
Ice-covered oceans could provide habitats for extremophiles.
Lake and River Structures:
Description of Titan’s surface, which features lakes and rivers of methane and ethane.
Comparison to Earth, highlighting the variety of organic compounds.
Ice Volcanoes on Titan:
Existence of ice volcanoes that erupt slushy material rather than molten rock like on Earth.
Energy and Solvent Issues:
The difficulty of life existing due to the chemical inefficiencies of methane and ethane as solvents.
Continued exploration of Jovian moons and their potential for hosting life needs to address many open questions.
Current beliefs and hypotheses remain under active investigation.