- Recently solar storm has hit Earth, which had the potential to knockout power supplies and spark impressive auroras.
What is a solar storm?
- Also known as a geomagnetic storm, it is a temporary disturbance of the Earth’s magnetic field, caused by radiation and streams of charged particles from the sun.
- The storms occur when the sun emits huge bursts of energy in the form of solar flares and what are known as “coronal mass ejections” (CME) – streams of charged plasma that travel at millions of miles an hour.
- These send a stream of electrical charges and magnetic fields towards the Earth at a speed of around 3,000mph.
- When a solar storm strikes it usually creates a spectacular “Northern Lights” display in parts of the atmosphere that can be seen in areas close to the Arctic Circle.
- In 2011 a CME produced a particularly powerful solar flare that disrupted radio communications throughout China.
- Scientists have discovered that the frequency of solar flares appears to follow an 11-year solar cycle.
When was the solar storm 2018?
- The space agency NASA predicted the solar storm, after it detected two gigantic solar flares erupting from the sun.
- The arrival of the solar storm coincided with the formation of "equinox cracks" in the Earth's magnetic field, which form around the equinoxes on March 20 and September 23 each year.
What causes solar flares?
- Solar flares occur when a build-up of magnetic energy on the sun is suddenly released.
- They usually erupt from sunspots, temporary dark and relatively cool patches on our star's surface where the local magnetic field is very strong.
- Flares generate a burst of radiation.
- Scientists classify strong solar flares into one of three categories: C, M or X (with A and B classes, too, for weaker eruptions).
- There's a tenfold increase in power from one class to the next, so an X flare is 10 times stronger than an M flare, and 100 times more powerful than a C.