Imagine you’re outside, ready to have fun with a barbecue and a game of badminton. Suddenly, you notice dark clouds in the sky. You might think of checking your phone for the weather, but your nose can actually tell you a lot!
Our noses are incredible! They can detect up to a trillion different smells. Some of these scents can remind us of special memories, like visiting your grandma’s house, playing with your first dog, or the fresh smell of rain.
Before a storm, the wind carries different smells. One of the most noticeable is a fresh, earthy scent. This smell comes from three main chemical sources. First, there’s ozone. Ozone is a special kind of oxygen that gets its name from a Greek word meaning “to smell.” When lightning strikes, it splits oxygen in the air, and some of it turns into ozone. The wind then carries this ozone ahead of the storm, and that’s what you smell.
As the rain starts to fall, you might notice another smell called “petrichor.” This word comes from Greek mythology, combining the essence of gods and the earth. Petrichor happens when rain hits the ground and mixes with organic materials and minerals in the soil. This creates a unique scent that fills the air.
When the soil is dry, certain chemicals stay in the ground. These chemicals tell plants to stop growing their roots or prevent seeds from sprouting until there’s enough water. Petrichor is like a signal for plants to be patient.
There’s also a special bacteria in the soil that releases a chemical called geosmin. Geosmin gives beets their earthy taste and adds to the smell of petrichor. This scent can even attract camels to water sources in the desert, helping spread soil bacteria across the sands. In rivers and lakes, petrichor might signal fish that it’s time to lay eggs.
Next time you smell a storm coming, take a moment to appreciate the story the earth is telling you. Stay curious and enjoy the wonders of nature!
Now, let’s talk about sharks. They might seem scary, like they’re waiting to attack, but that’s not true. Sharks are important for the ocean’s health, and we shouldn’t fear them. Instead, we should learn more about them and respect their role in the ocean ecosystem.
Become a smell detective! Go outside and try to identify different scents in the air. Write down what you smell and what you think might be causing those scents. Share your findings with the class and discuss how these smells might change before a storm.
Create your own “storm” in a jar to understand how ozone is formed. Use a glass jar, water, and a small piece of aluminum foil. Rub the foil with a wool cloth to create static electricity, then place it in the jar. Observe any changes and discuss how this relates to the formation of ozone during a storm.
Draw or paint a picture that represents the smell of petrichor. Think about the colors and scenes that come to mind when you imagine the earthy scent of rain hitting the ground. Share your artwork with the class and explain your creative choices.
Act out the role of soil bacteria and geosmin in the environment. Create a short skit showing how these bacteria release geosmin and how it affects plants, animals, and even humans. Perform your skit for the class and discuss the importance of these bacteria in nature.
Write a short story about a storm from the perspective of a raindrop or a gust of wind. Include descriptions of the smells and changes in the environment as the storm approaches. Share your story with the class and discuss how different elements of a storm can be described through the sense of smell.
Sure! Here’s a sanitized version of the transcript:
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[MUSIC] You’ve fired up the grill, set up the badminton net, and noticed some dark clouds on the horizon. Don’t check your phone; your nose knows!
[MUSIC] Our noses can detect up to a trillion different scents, many of which are deeply tied to our memories and emotions. Think of your grandma’s house, your first dog, or the smell of rain.
Storm winds carry a variety of scents, but the earthy odor that precedes a storm can be traced to three chemical sources. Before a thunderstorm, you’re likely smelling ozone, which gets its name from the Greek word meaning “to smell.” The electrical charge of lightning in approaching storm clouds splits oxygen gas into separate atoms, some of which can reform into ozone. It’s swept ahead of the advancing storm by windy downdrafts, reaching your nose.
As rain begins to fall, a new smell emerges from the soil: the pleasantly pungent scent we call “petrichor.” Petrichor gets its name from the essence that flowed through the veins of Greek gods and from the stones of the Earth, capturing both its science and the powerful feelings it evokes.
When decomposed organic material is blown airborne from dry soil, it lands on dirt or rocks, where it combines with minerals to create a unique mixture of molecules. Falling raindrops then send those chemicals into the air, right into your nostrils.
When there’s no rain, those same chemicals remain in the soil, signaling plants to halt their root growth or prevent seeds from sprouting when there’s no water available. Petrichor: it’s for the plant that’s tired of waiting to germinate.
Bacteria in the soil also contribute to petrichor by releasing a chemical called geosmin, which gives beets their earthy flavor.
Petrichor has other purposes too; it’s thought to attract camels to desert oases, who help transport the soil bacteria across the sands. Petrichor that washes into rivers and lakes also seems to signal fish that it’s time to spawn.
There’s nothing like a rainstorm to spark a little romance, I guess. So next time you smell a summer storm approaching, take a moment to think about what that rock over there is trying to tell you. Stay curious, and see you later!
Why are sharks so scary? They seem like bloodthirsty beasts lurking in the waves, waiting to feast on human flesh. If only we could get rid of them, our vacations would be so much safer, with nothing to worry about while we’re surfing and enjoying the ocean. Except that’s not the case.
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Let me know if you need any further modifications!
Noses – The part of the face that contains the nostrils and is used for smelling and breathing. – Dogs have very sensitive noses that help them detect different smells.
Smells – The odors or scents that are detected by the nose. – The smells of flowers and fresh grass filled the air during our science field trip.
Ozone – A gas made up of three oxygen atoms that is found in the Earth’s atmosphere and protects us from the sun’s harmful rays. – Scientists study the ozone layer to understand how it protects life on Earth.
Rain – Water that falls from clouds in the sky as droplets. – We learned in science class that rain is an important part of the water cycle.
Petrichor – The pleasant smell that often accompanies the first rain after a long period of warm, dry weather. – After weeks without rain, the petrichor was refreshing and made the garden smell wonderful.
Soil – The top layer of the Earth where plants grow, made up of organic matter, minerals, gases, liquids, and organisms. – In biology class, we examined different types of soil to see which was best for growing plants.
Bacteria – Microscopic living organisms, usually one-celled, that can be found everywhere and can be beneficial or harmful. – We learned that some bacteria in the soil help plants grow by breaking down nutrients.
Chemicals – Substances with a distinct molecular composition that are produced by or used in a chemical process. – Our science experiment involved mixing different chemicals to see how they reacted with each other.
Plants – Living organisms that typically grow in the ground, have leaves, stems, and roots, and use sunlight to make their own food through photosynthesis. – We observed how plants grow towards the light in our biology project.
Sharks – A group of fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. – In our science book, we read about how sharks are important predators in the ocean ecosystem.
