RESOURCE CARD 1: GOLDILOCKS VENUS Too much greenhouse effect: The atmosphere of Venus, like Mars, is nearly all carbon dioxide. But Venus has about 300 times as much carbon dioxide in its atmosphere as Earth and Mars do, producing a runaway greenhouse effect and a surface temperature hot enough to melt lead. The atmosphere on Venus is much denser than the ones on Mars or Earth. If we represented the density with beans, Venus would have 9000 beans compared to 100 on Earth. Temperature and Pressure Comparison Atmospheric Concentrations of Greenhouse Gases (%) on Venus Surface Pressure Relative to Earth 90 Carbon Dioxide (CO2) 96.5 Major Greenhouse Gases Nitrogen (N2) 3.5 CO2 Estimated Temperature if no -46 Oxygen (O2) Trace Greenhouse Gases (°C) Actual Temperature (°C) 477 Argon (Ar) 0.007 Temperature Change Due to GHG +523 Methane (CH4) 0 The relative distance from the Sun has some influence on planetary temperature, but the greenhouse gases and atmospheric density have more of an impact on temperature. Venus has an extremely dense atmosphere (with a surface pressure 90 times that relative to Earth's atmosphere). Conversely, Mars has an extremely thin atmosphere (with a surface pressure less than 1/100th of that relative to Earth's atmosphere). RESOURCE CARD 2: GOLDILOCKS MARS Not enough greenhouse effect: The planet Mars has a very thin atmosphere, nearly all carbon dioxide. Because of the low atmospheric pressure, and with little to no methane or water vapor to reinforce the weak greenhouse effect, Mars has a largely frozen surface that shows no evidence of life. Temperature and Pressure Comparison Atmospheric Concentrations of Greenhouse Gases (%) of Mars Surface Pressure Relative to Earth 0.007 Carbon Dioxide (CO2) 95 Major Greenhouse Gases Nitrogen (N2) 2.7 CO2 Estimated Temperature if No -57 Oxygen (O2) 0.13 Greenhouse Gases (°C) Actual Temperature (°C) -47 Argon (Ar) 1.6 Temperature Change Due to GHG +10 Methane (CH4) 0 The relative distance from the Sun has some influence on planetary temperature, but the greenhouse gases and atmospheric density have more of an impact on temperature. Mars has an extremely thin atmosphere (with a surface pressure less than 1/100th of that relative to Earth's atmosphere). RESOURCE CARD 3: GOLDILOCKS EARTH The right amount of greenhouse effect? The Earth has small amounts of carbon dioxide and other greenhouse gases, but working together they create a balanced system that helps to support life. US! This model does not take into account the importance of water vapor as a greenhouse gas. Water vapor both helps warm the planet, when it is in the form of a gas, and cool the planet, when it is in a reflecting cloud. Temperature and Pressure Comparison Atmospheric Concentrations of Greenhouse Gases (%) on Earth Surface Pressure Relative to earth 1 Carbon Dioxide (CO2) 0.03 Major Greenhouse Gases Nitrogen (N2) 78 H2O, CO2 Estimated Temperature if No -18 Oxygen (O2) 21 Greenhouse Gases (°C) Actual Temperature (°C) 15 Argon (Ar) 0.9 Temperature Change Due to +33 Methane (CH4) 0.002 Greenhouse Gases The relative distance from the Sun has some influence on planetary temperature, but the greenhouse gases and atmospheric density have more of an impact on temperature. Venus has an extremely dense atmosphere (with a surface pressure 90 times that relative to Earth's). Conversely, Mars has an extremely thin atmosphere (with a surface pressure less than 1/100th of that relative to Earth's). .