Shield or Oven? Greenhouse Effect on Planets Quiz

If a celestial body has sufficient mass to exert a gravitational pull, and if that pull prevents gas molecules from escaping into space, then those gases form a stable layer known as an atmosphere.

If solar radiation passes through an atmosphere to warm a planet's surface, and if the surface then emits that energy back as long-wave infrared radiation, then certain gases will absorb and re-radiate that heat back toward the surface rather than letting it escape into space.

If a gas molecule has three or more atoms, it can vibrate in ways that allow it to absorb infrared photons; if CO2, CH4, and H2O fit this molecular structure while N2 and O2 do not, then only the former are effective greenhouse gases.

If a planet has an extremely high concentration of a potent greenhouse gas, and if Carbon Dioxide is the dominant gas on Venus, then the resulting heat-trapping effect will create the highest surface temperatures in the solar system.

If greenhouse gases act as an insulating blanket, and if adding more insulation reduces the amount of heat that can escape per second, then the planet must reach a higher equilibrium temperature to balance the incoming solar energy.

If Earth had no greenhouse effect, its average temperature would be about -18 degrees Celsius, which is below the freezing point of water; if the greenhouse effect keeps Earth's temperature at a life-sustaining 15 degrees Celsius, then the effect is necessary for habitability.

If gas molecules move faster when hot (temperature), and if they must exceed a certain speed to leave (escape velocity), then gravity and heat determine retention; if the solar wind can strip away gas, then a magnetic field is also required for protection.

If "albedo" measures the fraction of light reflected from a surface, and if a higher albedo means less energy is absorbed by the planet, then this value directly impacts the initial heating before the greenhouse effect begins.

If the greenhouse effect depends on the total number of heat-trapping molecules, and if the atmosphere of Mars is less than 1% as dense as Earth's, then there are not enough CO2 molecules to provide significant warming regardless of the gas type.

If the greenhouse effect requires a layer of gas to absorb outgoing radiation, and if Mercury's proximity to the Sun and low gravity result in a nearly vacuum-like exosphere, then heat cannot be trapped, leading to extreme temperature swings.

If the Sun emits most of its energy as high-energy visible light, and if planets re-emit energy as lower-energy heat, then the greenhouse effect relies on the fact that atmospheres are transparent to short-wave visible light but opaque to long-wave infrared radiation.

If CO2 is moved between the atmosphere, oceans, and rocks through weathering and volcanism, and if this movement balances the atmospheric composition, then the carbon cycle is the primary regulator of Earth's long-term climate.

If a feedback loop occurs where heat causes more gas release (like water vapor), and if that gas causes even more heat, then the oceans will boil away; if this process is irreversible on human timescales, it is a runaway effect, as seen on Venus.

If habitability depends on temperature, and if the greenhouse effect can raise a planet's temperature by hundreds of degrees, then a planet's atmospheric composition is just as important as its distance from the star in determining if water remains liquid.

If gravity pulls gas molecules toward the center of the planet, and if the molecules at the bottom are supporting the mass of all molecules above them, then the resulting force per unit area is defined as atmospheric pressure.

If the Gas Giants formed far enough from the Sun to capture the most abundant elements from the solar nebula, and if hydrogen and helium were the most common, then those gases dominate their massive atmospheres.

If a planet's temperature is to remain stable, it must emit exactly as much energy as it absorbs; if it absorbs more than it emits, it warms up until the increased heat causes it to emit more, eventually reaching a state of radiative equilibrium.

If greenhouse gases allow sunlight to reach the surface (transparent to visible) but block heat from leaving (opaque to infrared), and if molecules like CO2 and CH4 are common volcanic byproducts, then these characteristics define their role in planetary science.

If industrial processes release billions of tons of sequestered carbon from fossil fuels into the atmosphere annually, and if ice core data shows CO2 levels rising at unprecedented rates, then the conclusion is that human activity is the primary driver of current atmospheric change.

If Titan is a moon of Saturn with a dense atmosphere (1.5 times Earth's pressure), and if it is composed mostly of nitrogen and methane, then it demonstrates that even moons can have complex greenhouse effects and weather systems.