Compared to the Sun, Earth’s magnetic field isn’t very complicated – it’s like that experiment we did as kids with a bar magnet, a piece of paper, and iron filings, but in 3D.
But because our Sun is basically one big, hot ball of plasma, and doesn’t all rotate at the same speed like Earth, its magnetic field gets very complicated. And these fluctuations are the main drivers for the incredible eruptions from its corona, the outermost part of the Sun’s atmosphere. These can be extreme bursts of radiation, called solar flares. Or they can be massive eruptions of its plasma, known as coronal mass ejections, or CMEs.
These are the two main events that cause impacts here on Earth and in near-Earth space. At the Australian Space Weather Forecasting Centre, we monitor the Sun all day, every day. We’re watching from satellites pointed towards it, and also from Earth-based optical and radio telescopes. If a solar flare occurs, it arrives here as a burst of radiation travelling at the speed of light. That means it has travelled 150 million kilometres in just eight minutes. A coronal mass ejection, on the other hand, is not quite as fast. They can take anywhere from 14 hours up to about three days to arrive.
When we see one of these events occur, we model it to try and understand which direction it’s travelling – whether it’s going to be shot out into space or whether it’s coming towards us. If it’s going to be coming towards Earth, we then want to know how long it will take to get here, and how big we expect the impact to be. We then issue warnings from those predictions.
These can be seen through our website, but we also have email alerts as well, or deliver warnings directly to our key customers.
Why does it matter if the Sun has an eruption when it’s so far away from us?
Most people know about auroras, which can be seen near the…
Ad Amazon : The reality of UFOs and extraterrestrials is here for those with the courage to examine it. We are not alone! We are only one of many different humanoids in a universe teeming with other intelligent life?