On Sunday, Earth’s magnetic field was attacked by a solar wind stream that reached speeds of more than 600 kilometers (372 miles) per second.
Although this is not too alarming – solar storms often hit our planet causing spectacular auroras – what is strange is that this storm was completely unexpected.
“This event was not in the forecast, so the resulting auroras were a surprise,” SpaceWeather reported.
The solar wind occurs when a stream of high-energy particles and plasma can no longer be contained by the Sun’s gravity and bursts toward Earth.
There’s a lot we still don’t know about how our Sun works, but these emissions are thought to come from large bright spots on the Sun known as ‘coronal holes’, and scientists are doing a great job of monitoring them from here on earth.
Through this tracking, they are able to create space weather “forecasts” that not only predict when solar storms or solar flares, also known as coronal mass ejections (CMEs), are headed our way, but also the force they will be
But that doesn’t mean we can’t still surprise ourselves like we did at the weekend.
Early Sunday, NASA’s Deep Space Climate Observatory (DSCOVR) noticed light solar wind streams, which increased significantly and unexpectedly throughout the day.
The cause of this solar storm is still unknown, but SpaceWeather speculates that it could have been the early arrival of the solar wind that is expected to come from an equatorial hole in the Sun’s atmosphere two days later.
Or it could have been a missed coronal mass ejection (CME).
“A discontinuity in the solar wind data at 0045 UT on August 7 hints at a shock wave embedded in the solar wind,” Space Weather writes.
“These days, the active sun is producing so many minor explosions, it’s easy to miss weak CMEs headed for Earth.”
At the time of writing, the high-speed solar wind continues to slam into Earth’s magnetic field, with records showing speeds reaching 551.3 kilometers (343 miles) per second on August 9 at 0406 UTC (0006 ET).
The good news is that the solar wind does not harm us here on Earth, safely protected by our planet’s atmosphere.
When it’s strong, however, it can affect our technologies, causing problems with telecommunications satellites and, in extreme cases, power grids.
These winds were classified as a moderate G2 solar storm – storms are classified as G1 at the lowest end of the scale to G5, which is a powerful solar storm.
G2 storms can affect high-latitude power systems and could affect spacecraft orbit predictions, according to Space Weather.
If this all sounds familiar to you, it’s because we’ve seen plenty of solar storms this year, with the Sun now in the active phase of its 11-year solar cycle.
This year we have already been hit by X-class flares and giant coronal holes, more than 2.5 times the size of Earth. Most of the time you would have no idea this is going on.
Unless you’re an avid aurora watcher, that is.
Fortunately, followers of the Space Weather Warning Service were notified of the unexpected storm and were able to see the resulting powerful auroras and Steve, which was seen as far south as Pennsylvania.
“I was already in bed getting ready for sleep when the storm started,” astrophotographer Ruslan Merzlyakov told Space Weather.
“Running on Nykøbing Mors beach, I was able to photograph the first summer auroras in Denmark in 5 years.”
Who knows what the rest of the week has in store for us.