Earth, weather and climate

55 to explore · page 2 of 2

• Watch What If? Lab What if hurricanes could be steered? Hurricanes are huge spinning storms that grow over warm ocean water. Nobody can steer or stop one today: a hurricane holds far more energy than people could ever push around. What people can do is forecast where it may go and get ready early. Imagine steering one, then see why forecasts are the real answer.
• Watch What If? Lab What if snow were black? Clean snow is white because it reflects most of the sunlight that hits it, which helps it stay cold and frozen. Dark things soak up sunlight and warm up. In some mountains, dust blowing onto snow already makes it melt weeks earlier. Imagine snow that was black, and find out why color matters so much.
• Watch What If? Lab What if the air were full of dust? Every year, winds lift millions of tons of dust from the Sahara Desert and carry it across the Atlantic Ocean. Dust and other tiny particles in the air can color sunsets red, make the sky hazy and get into our lungs. Imagine air that was always full of dust, and find out why clean air matters.
• Watch What If? Lab What if the continents stopped moving? Earth's outer shell is broken into giant plates that creep along just a few centimeters a year. Where they meet, they build mountains and cause earthquakes and volcanoes. Imagine the plates stopped: rain, ice and wind would keep wearing the land down, but nothing would push new mountains up.
• Watch What If? Lab What if the ground were made of limestone? Limestone is a rock that rainwater slowly dissolves. Over thousands of years, water seeping through it carves caves, opens sinkholes and bubbles back up as springs. About a fifth of the land in the United States is already this kind of landscape, called karst. Imagine the ground everywhere were limestone, and find out what would happen to the rain.
• Watch What If? Lab What if weather forecasts were always right? NOAA said in 2025 that a five-day weather forecast is right about 90 percent of the time, but a ten-day forecast is right only about half the time. Why? Because tiny changes in the air can grow into big differences, an idea called the butterfly effect. Imagine forecasts that were never wrong, and discover the satellites, balloons and supercomputers that make today's forecasts so good.
• Watch What If? Lab What if you found a meteorite? Meteorites are pieces of space rock that survived a fiery trip through Earth's air. Most come from asteroids, a few from the Moon or Mars, and many are older than any rock ever found on Earth. Imagine finding one: learn the clues scientists look for, what is inside, and why the right first step is to tell a grown-up and ask a museum or university.