Deserts
A fifth of the land on Earth is a desert. They are defined not by heat, but by how incredibly dry they are. Because water is in such short supply, the plants and animals that live here have developed bizarre adaptations to survive. Let us explore how life thrives in the extremes!
The Dry Zones!
No, some are freezing cold! Antarctica is actually a desert. The cold air holds so little moisture that some places down there have not seen snow or rain in over 100 years. Furthermore, only 20 percent of the world's deserts are actually covered in sand.
To save water and stop thirsty animals! Normal leaves are too thin and would lose water to evaporation way too quickly. The spines keep animals away from the wet, spongy tissue stored safely inside the plant.
Test Your Survival Instincts
Think about how plants and animals could possibly survive with almost no water. Pick an answer below to test your ecological knowledge.
It catches the fog! This beetle props its body up at night. When the desert fog rolls in, moisture condenses on the beetle's hard shell and drips directly down into its mouth.
There are no clouds! During the day, the sand gets very hot. At night, because the sky is completely clear, all that heat radiates instantly away into the icy blackness of space.
Life in the Extremes
Tap each card to uncover the geological weather patterns that create deserts and the biological tricks animals use to survive in them.
Key Concepts
What is a Desert?
Tap to learn moreA desert is scientifically defined as an area of land that receives less than 10 inches of annual rainfall. Heat is not the defining factor; dryness is.
The Rain Shadow
Tap to learn moreAs wind blows moist air up a mountain, the air cools and drops its moisture as rain. By the time the air goes over the peak to the other side, it is completely dried out, creating a desert.
Cold Deserts
Tap to learn moreNot all deserts are hot. Antarctica is a freezing cold desert. Cold air cannot hold as much water vapour as warm air, so the moisture freezes out, leaving the air incredibly dry.
Nighttime Freezes
Tap to learn moreHot deserts get very cold at night. Because there are usually no clouds to act like a blanket, the heat from the sand escapes rapidly into space.
Cactus Adaptations
Tap to learn moreCactuses are green all over to absorb sunlight without needing thin leaves. They are filled with spongy tissue that stores precious water, and covered in spines to keep animals away.
Burrowing Animals
Tap to learn moreMany desert animals burrow deep into the sand to stay cool. The underground soil acts as natural insulation, saving their body water during the blistering heat of the day.
Creative Drinking
Tap to learn moreA specific desert beetle props its body up at night so desert fog condenses on its shell. The water then drips down the shell directly into its mouth.
Desert Soils
Tap to learn moreDesert soil has very little decaying plant and animal material in it because so few things live there. Wind blows away the surface dirt, leaving behind hard clay, gravel, and sand.
Interactive: Rain Shadow & Temperature Simulator
Control the atmospheric wind patterns. Push the cloud over the mountain to observe the rain shadow effect and watch the live telemetry dashboard track the moisture loss. Toggle nightfall to observe desert heat radiation.
Apply Your Knowledge
Let us see if you can correctly identify the essential ecological terminology associated with the desert biome.
Match the Concepts
Click a scientific term to select it, then click the matching description to place it.
Design a Desert Rover
Imagine you are designing a robotic rover to explore a hot desert for scientists. Based on how desert animals and plants adapt to the harsh environment, describe two specific features you would build into the robot to keep its computers from overheating during the day and freezing at night.
What Has Changed Since This Episode Aired
This episode originally aired in 1996. Since then, environmental science and technology have advanced significantly!
Updated: Bill Nye highlighted a beetle that cleverly collects fog on its body. Today, scientists have engineered biomimetic materials modelled directly after this beetle's back to pull clean drinking water directly out of thin air in arid climates!
Updated: Deserts naturally cover a fifth of the Earth. However, climate change and overfarming are currently causing deserts to expand rapidly into green areas, a highly dangerous global process known as desertification.
Updated: Deserts were mostly viewed as harsh, empty environments. Now, thanks to the constant lack of clouds, deserts around the world are becoming global hubs for massive solar panel farms, generating clean energy for millions of homes.
Updated: The expert noted that Antarctic ice is centuries old. Now, glaciologists are drilling miles deep into Antarctic ice cores to study air bubbles that were trapped millions of years ago, giving us a perfect record of Earth's ancient atmosphere.
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