Earth's Life Sustaining Atmosphere PDF

Characteristics That Enable Life on Earth 7.9C Name: Period: Date: Literacy Connection: Earth’s Life Sustaining Atmosphere The atmosphere is like...

Characteristics That Enable Life on Earth 7.9C Name: Period: Date: Literacy Connection: Earth’s Life Sustaining Atmosphere The atmosphere is like an invisible protector that surrounds our planet. It is Earth’s life-support system, creating the conditions that make our planet a unique and habitable place for a diverse array of living organisms. There are several layers of the atmosphere, and each has specific characteristics. Even though life would not exist on Earth without its atmosphere, it is actually pretty thin! A good analogy to represent how thin the atmosphere VOCABULARY really is would be to lay a piece atmosphere of paper over a the layer of gases basketball. The surrounding a planet basketball represents Earth, and the piece of paper represents the atmosphere’s thickness in comparison! The Greenhouse Effect and Solar Radiation VOCABULARY Beyond being a source of the air we breathe, the atmosphere regulates Earth’s temperature, preventing greenhouse effect extreme heat fluctuations between the night and day. a natural process in which gases The greenhouse effect is the reason for this. It is a in Earth’s atmosphere, such as process in which gases in Earth’s atmosphere trap carbon dioxide and water vapor, the Sun’s energy, preventing it from escaping back trap the Sun’s energy, preventing it into space. If the greenhouse effect didn’t act like a from escaping back into space “blanket” keeping the warmth in, it would be extremely cold on the night side and extremely hot on the day side of Earth! The Moon experiences these extreme temperature shifts because it has no atmosphere. On the day side of the Moon, the 4 1 temperatures reach 127°C (260°F), while the night side temperatures plummet to −173°C (−280°F). Due to the similar distances of the 2 Moon and Earth from the Sun, we can predict what Earth’s temperatures would be like without our atmosphere. 3 3 Characteristics That Enable Life on Earth The atmosphere also keeps the Sun’s harmful ultraviolet (UV) rays away from Earth’s surface. The ozone layer absorbs much of the UV radiation, protecting life on Earth. Skin cancer and cataracts are just two health conditions that result from too much exposure to UV radiation and are greatly reduced due to the atmosphere. Earth’s Atmosphere and Photosynthesis VOCABULARY Did you know that without the atmosphere, photosynthesis couldn’t occur on Earth? photosynthesis Photosynthesis is the process by which plants make the process by which plants make their own food by transforming radiant energy into their own food by transforming chemical energy in the form of glucose. Just based on radiant energy into chemical the definition of photosynthesis, it may not sound like energy in the form of glucose the atmosphere plays a role in this process. However, carbon dioxide is essential for photosynthesis to occur. Plants absorb carbon dioxide from the air through tiny pores on their leaves called stomata. During photosynthesis, plants use water, sunlight, and carbon dioxide to produce glucose. Oxygen is then produced and released into the atmosphere. This exchange of gases between the atmosphere and plants ensures a continuous supply of much- needed oxygen for us on Earth Stomata in leaves open to take in carbon dioxide and release oxygen, and close to reduce water loss through evaporation. Conclusion Though other planets have some similarities to Earth, none have an atmosphere that is able to support life like Earth’s is. Venus, for example, has been referred to as Earth’s “sister planet” due to similarities in size, mass, and composition. However, Venus’ extremely thick atmosphere is composed of carbon dioxide with clouds of sulfuric acid, creating an environment in which it would be impossible to breathe. Venus’ atmosphere traps heat so well that thermal radiation cannot escape the planet. This prevents the planet from cooling, causes extremely high Venus’ thick carbon dioxide temperatures (up to 460°C; 860°F), and causes any water present to atmosphere and surrounding layer of sulphuric acid clouds make the boil into steam immediately. If you found yourself on Venus, you would planet appear orange and dusty. have to dodge droplets from sulphuric acid clouds, which are caustic enough to burn a hole through your skin. But before that could happen, you would likely die due to severe burns as a result of the planet’s extreme temperatures. So, the next time you step outside, take a deep breath, and feel the warmth of the Sun’s rays on your skin, thank Earth’s atmosphere for making the planet such a safe and beautiful place to live! 4 ©2023 Summit K12 Holdings, Inc.