What causes the sun to produce solar flares and coronal mass ejections (CMEs)?
The sun is the main source of energy for life on Earth. It might look small from far away, but it is a huge ball of hot gases with very strong magnetic fields. Its surface temperature is around 5,500°C, and it is about 1.4 million kilometres wide.
The sun has strong magnetic fields that can sometimes twist or break. When this happens, a lot of energy is released suddenly. This creates two things:
- Solar flares – bright flashes of light and energy from the sun.
- Coronal Mass Ejections (CMEs) – big clouds of hot gas and magnetic fields that are thrown out into space.
These explosions usually happen in the sun’s outer part called the corona, which is very hot (about two million degrees Kelvin) (NASA, 2023).
CMEs take about 15 to 18 hours to reach Earth. When they do, they can cause geomagnetic storms. These storms can:
- Affect satellites and phones.
- Cause power blackouts.
- Be dangerous to astronauts in space.
Solar flares can disturb Earth’s magnetosphere and ionosphere, especially if Earth is directly in their path. They effects can be felt in minutes or hours.
Scientists study space weather so they can warn people early before big solar storms happen. This helps protect things like:
- Satellites and communication systems.
- Power stations.
- Planes and astronauts.
Many countries are now putting a lot of resources into space research to learn more about how the sun behaves.
We now understand more than before, but we still need to be prepared for big storms from the sun.
Sources:
- NASA (2023). Solar Flares and CMEs. https://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html
- NOAA (2022). Space Weather Info. https://www.swpc.noaa.gov
- ESA (2023). The Sun and Space Weather. https://www.esa.int/Science_Exploration/Space_Science/Solar_Orbiter
- Schrijver, C. J., et al. (2015). Understanding Space Weather to Shield Society. Nature Communications.