TIM: Animals in cold deserts have the opposite problem. TIM: They come out a night when it's cooler.Īn animation shows a scorpion walking at night. Eyes peer out of a shady spot in a plant. In hot deserts, most animals sleep below ground or in patches of shade during the day.Īn animation shows sleeping animals in holes below ground on a sunny day. It takes special types of plants and animals to survive in them. TIM: But hot or cold, deserts are some of the harshest environments on the planet. TIM: By the time any clouds arrive from the coast, they've most likely already dumped all their rain. The global map shows Tim and Moby at the Gobi Desert in Asia. Asia's Gobi Desert formed because it's so far away from the ocean. TIM: Local geography has a big impact on arid regions, too. Tim and Moby are transported to another desert. Moby presses the transporter button in his wrist. TIM: Most organisms in polar deserts live near the coasts, where the oceans provide food and temperatures are a bit warmer.Ī group of penguins hold their wings up while making sounds and bow at Moby. The thermometer reads minus eighty-nine degrees Celsius. And Antarctica has the lowest temperatures on record.Īn image shows a person holding a thermometer near a trailer equipped with a satellite dish. TIM: Well, the colder the air, the less moisture it can hold. The penguin holds its wings up, make sounds, and bows to Moby. TIM: This is the Antarctic desert, and it's the biggest in the world. High-pressure systems and cold ocean currents near the earth's poles are responsible for the polar deserts.Ī global map shows the highlighted polar deserts to the north and south. A penguin exchanges looks with Tim and Moby. Moby presses a transporter button in his wrist. Deserts cool off fast once the sun goes down. TIM: With so little water to cool the land and air, temperatures in hot deserts can reach over fifty-five degrees Celsius, or more than one hundred thirty degrees Fahrenheit. TIM: All that hot, dry air means lots of evaporation.Īn image shows a body of water evaporating in a desert. TIM: And the Sun's rays hit the earth pretty directly here.Īn animation shows arrows pointing to where the sun hits the globe. Arrows show the conditions that produce high pressure in the belts. TIM: Permanent areas of high pressure in these latitudes keep dry air circulating near the planet's surface.Īn animation shows the two belts where hot deserts occur on a globe.
The equator and thirty degrees north and south of it are shown on the world map of arid regions.
Hot deserts, like the Sahara in Africa, are found in two belts, around thirty degrees north and south of the equator.
TIM: Well, a desert's climate is mainly a factor of where it is on the planet. Side by side images show a rocky and a sandy dunes arid region. Some are covered in huge hills of sand called dunes, which are shaped and pushed around by the wind. TIM: Because moisture prevents soil erosion, arid regions are usually pretty rocky. TIM: Deserts are also known as arid regions, and they're the driest places on Earth. There are hot deserts, cold deserts, and sort of in-between deserts, too. TIM: Actually, deserts don't have to be hot, like this one, just very dry. TIM: Dear Tim and Moby, What makes a desert so hot? From, Wei-Ling. Tim and Moby appear under a tree in a desert. The scene spins away to Tim, with no beard, wearing a towel on his head. Text reads: The Mysteries of Life with Tim and MobyĪ boy, Tim, is lying on his back on sand.Ī robot, Moby, is lying on his back next to Tim.
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