Final answer:
Carbon dioxide in Mars's atmosphere contributes to the greenhouse effect by producing absorption bands in the infrared portion of its spectrum, similar to those observed in Earth's atmosphere, affecting Mars's surface temperature and planetary habitability.
Step-by-step explanation:
Carbon dioxide in Mars's atmosphere produces absorption bands in the infrared portion of its spectrum. On Mars, the presence of carbon dioxide in the atmosphere contributes to the greenhouse effect, although to a much lesser extent compared to Earth or Venus. The high resolution infrared emission spectrum taken from Earth's atmosphere reveals absorption bands associated with CO2 that are similar to what would be expected from Mars's atmosphere. In an emission spectrum, an absorption band appears as a range of wavelengths where light is absorbed by the substance in the atmosphere, in this case, CO2. The CO2 band observed between 600 and 700 cm⁻¹ in infrared spectra indicates where CO2 absorbs infrared radiation. Meanwhile, the absorption of infrared radiation by CO2 on Mars contributes to the trapping of thermal energy, providing what little greenhouse warming occurs there, given its thin atmosphere.
The importance of understanding absorption by greenhouse gases such as CO2 in planetary atmospheres extends beyond Mars. It is a critical aspect of planetary habitability, influencing surface temperatures and potentially the ability to support life. The absorption and emission characteristics of greenhouse gases help scientists determine the climatic conditions of planets and the potential for the presence of life on them.