NASA
What is Space Weather?
You know about the weather on Earth. If someone asks you about the weather in your city today, you might say whether or not it's cloudy, whether rain or snow is falling, or if it's windy.
"Weather" in Space?
But did you know that there is a weather in space too? When you hear someone talk about "space weather", they are talking about conditions in space that change from time to time. These changing conditions could be the amount of radiation from the Sun or how the the "solar wind" is flowing that day. Even magnetic fields in space can affect space weather. Changes in radiation, the solar wind, and magnetic fields make up space weather, just like changes in temperature, rainfall, and winds make up weather on Earth.
Space Weather Starts at the Sun
The amazing amount of energy the Sun gives off is what makes space weather go. Sometimes there are storms on the Sun, and these storms fling showers of radiation and powerful magnetic fields out into the Solar System. Most storms miss Earth, but some storms hit our planet. Those are the space weather storms we care about the most!
Space Weather Around Earth
When space weather from the Sun reaches Earth, it runs into a sort of magnetic bubble that surrounds the Earth called the "magnetosphere". How do space weather storms affect Earth? This depends on what the kind of storms from the Sun. It also depends on how those storms interact with the Earth's magnetosphere.
Changing Space Weather
Like weather on Earth, space weather is always changing. Just like Earth's weather changes with the changing seasons, space weather changes with a 11-year long sunspot cycle. At different times in the cycle, the Sun will be more stormy or more calm.
Space Weather and People - Why Should I Care?
Why are people interested in space weather? The Sun is the main source of energy for our planet. It makes plants grow and makes our weather go. Changes in the Sun could make a big change in our weather and climate on Earth. Storms from the Sun can hurt satellites, like the ones used for cell phones. That radiation can also hurt astronauts if they are in space when a storm comes. Really big space weather storms can even knock out the electricity over large areas. But not everything about space weather is bad. Sometimes storms makes really cool light shows. These light shows are called the aurora, or the Northern Lights and the Southern Lights.
