Solar wind
The Sun emits electrically charged particles. Because the Sun is mostly hydrogen, these particles are mainly protons and electrons. They travel through space at hundreds of kilometers per second. When solar activity increases, the solar wind becomes stronger and more variable.
The Sun’s outer atmosphere, the corona, is extremely hot—millions of degrees Celsius—causing particles to flow outward rapidly, forming the solar wind. In addition, powerful explosions called solar flares can occur near sunspots and intensify the solar wind. Large eruptions called coronal mass ejections (CMEs) also significantly affect the strength of the solar wind.
The Effects of the Solar Wind on Earth
The solar wind, a powerful stream of charged particles, affects Earth in several ways. It can cause:
- auroras
- satellite malfunctions
- GPS and communication disruptions
- power outages (rarely)
Most of these effects are disruptive, except for auroras, which are a natural spectacle.
Aurora
Earth is surrounded by a magnetic field that protects life from the solar wind. Most particles are deflected, but some are guided toward the North and South Poles. There, they collide with oxygen and nitrogen atoms at altitudes of about 80–300 kilometers, releasing energy as light—this is the aurora. The colors depend on the types of particles involved.
On other planets,
Mars does not have a strong magnetic field like Earth, so it is more exposed to the solar wind, which could be a challenge for future human settlement.
Jupiter and Saturn have strong magnetic fields, and auroras are observed where the solar wind interacts with their magnetospheres.