How is Earth Unique? 1. Among the planets in our solar system, Earth is unique b
ID: 296514 • Letter: H
Question
How is Earth Unique?
1. Among the planets in our solar system, Earth is unique because water exists in all three states (solid, liquid, and gas) on and near its surface. How would Earth’s hydrologic cycle be different if (a) its orbit was inside the orbit of Venus? (b) its orbit was outside the orbit of Mars.
2. What percent of Earth's atmosphere is oxygen, and why is it there?
3. What are extremophiles, and how does the study of them assist us in searching for life on other planets and moons?
4. If Earth had the same irregular style of global volcanic activity as Venus, why would that have made our planet less habitable for the evolution of complex life?
5. List at least one way the large oceans on Earth have made our planet much more habitable?
Explanation / Answer
1)a if the earth's orbit is inside venus, our atmosphere become more active than today because the driving force of the activities are from the solar energy, so when earth becomes more closer to sun it receives more sun light cause more water to evaporates from the ocean, so the precipitation will be much more and phenomenons such as hurricanes will be more frequent.
b)if the orbit is beyond mars it will become more calm, because most of the atmospheric phenomenons will died out due to the lack of enough solar energy so evaporation will considerably reduce, and most of the water will appears as ice blocks over the earth's surface.
2) around 21% of atmosphere is oxygen, and 78% is nitrogen, oxygen is continuesly fromed in the atmosphere during day time as a result of photosynthesis by the plants, and animals respirate it, so the amount of oxigen is maximum with in the troposphere and it will be here due to the gravity of earth.
3)extremophiles are organisms which can survive extreme living conditions in which other orgaisms will die, these organism are found areas where temperature is very high, low, acidic,alkaline, high uv radiations,salinity and at high pressure regions. so, these extreme conditions can be observe in another planets and moons so, there is a chance to survive these organisms in that conditions also, because no other organism will not be capable of live in such conditions so study of these organism will help in the search of lives outside earth.
4) volcanic activity on earth are associated with plate boundaries and hotspots, all other places are safe from such activities, if the earth has global volcanic activity like in venus the life on earth would be different, because the volcanic activity will vanish a group of organisms during its eruption, that will prevent the growth of the living organism in such environment.
5) Sun light and oceans are the two factors supporting the lives on earth, water is an important factor for the growth of life on earth, oceans will supply the enough water as precipitation as a result of the evaporation by the sun light, and that cherish the growth of plants an trees. so the oceans has a paramount role on making earth more habitable.