Beginning of Essay
The fragile balance of the Earth's ecosystem is constantly being disrupted. Overpopulation is placing heavy strain on the world's resources. We are burning all our fossil fuels to create the energy we need, and clearing our rainforests to make enough farmland to ....

Middle of Essay
.... a red, rocky, barren desert with little atmosphere, no water, and containing no life. If Earthlings were to settle on Mars, we would remain totally dependent on the Earth's resources. Another close planet is Venus, the second from the sun. This "sister planet" of Earth proved to have extremely hostile conditions. Scientists were hopeful when they found traces of water vapor in the upper atmosphere, but were disappointed when concentrations of sulphuric acid were discovered mixed with the water. Venus has surface temperatures of around 600 degrees Fahrenheit, and an atmosphere one hundred times as thick as the Earth's. (This produces pressure eq ....