The Sun is an active, glowing ball of very hot gas. Besides giving out light and heat, it also releases bursts of energy and streams of charged particles. These events are called solar activities, and they can affect the Earth. The conditions in space caused by the Sun are known as space weather.
Activities of the Sun
- Sunspots: darker, cooler patches on the Sun's surface.
- Solar flares: sudden, powerful bursts of energy and radiation.
- Solar prominences: huge loops of glowing gas above the surface.
- Solar wind: a continuous stream of charged particles flowing out from the Sun.
Key idea
The Earth's magnetic field and atmosphere act as a shield, protecting living things from most of the harmful solar particles and radiation.
Effects on Earth
When charged particles from the Sun reach Earth, they can produce beautiful glowing lights in the sky near the poles called auroras, seen as curtains of green, red and purple light. Strong solar activity can also disturb satellites, damage power grids, and disrupt radio and GPS communications. Astronauts in space face a higher risk from this radiation than people on the ground. Scientists watch the Sun closely and give space weather warnings so that satellites and power companies can prepare for the strongest events. Aeroplanes flying over the polar regions may also change their routes during a strong solar storm to keep their crew and radio contact safe.
Remember
- Solar activities: sunspots, flares, prominences, solar wind.
- Space weather is caused by the Sun.
- Earth's magnetic field protects us.