The sun has seen a flurry of activity on its surface recently and now NASA astronomers have seen not one but two ‘coronal holes’ in our star.
The first ‘hole’ or ‘sunspot’, 30 times the size of Earth, was discovered earlier this month and triggered a severe geomagnetic storm that put satellites on high alert and sparked Aurora borealis at very low latitudes.
The most recent hole discovered this week is smaller but still roughly 18 to 20 Earths wide in size.
The appearance of the latest hole has prompted the US National Oceanic and Atmospheric Administration (NOAA) to issue an alert for an increase in solar wind towards the end of the week, providing another chance to see the northern lights.
The coronal hole is expected to send solar winds of up to 1.8 million mph toward Earth on Friday.
“Arctic auroras are likely when the solar wind arrives,” said a alert at Spaceweather.com.
Solar winds can damage satellites at their worst, but for people on Earth, they can provide an opportunity to spot stunning auroras.
What is a coronal hole?
Coronal holes are not exactly literal holes in the Sun, but are large areas that are much cooler than the rest of the Sun, causing them to appear black.
These are places where the Sun’s magnetic field lines don’t close in on themselves, but stick straight out into space. This leaves an open channel for the solar wind to pass through.
A solar flare is an intense burst of radiation from the release of magnetic energy associated with these sunspots.
Flares are the largest explosive events in our solar system. They look like bright areas on the Sun and can last from minutes to hours.
What happens if a solar flare hits Earth?
That largely depends on the size of the solar flare: very small might be fine, but bigger ones could have catastrophic consequences.
The smaller ones, the C-class, are unlikely to have much of an impact on Earth, the medium-sized ones, known as the M-class, could cause some low-level damage, while the larger ones, known as the X-class, could be very harmful.
the biggest solar flares they are known as ‘X-class flares’, which are becoming routine. So far, the Sun has produced seven X-class solar flares this year.
Radiation from the latest flare ionized the upper part of Earth’s atmosphere, causing a strong shortwave radio blackout in Southeast Asia, Australia, and New Zealand.
If you’re hearing a lot about solar flares recently, it’s because the Sun is at its most active. This happens about every 11 years, when coronal holes are most likely to appear.
Since December 2019, solar activity has increased, including the number of sunspots and solar flares.
The Sun is heading towards a solar maximum, in 2024, when the star’s polarity will reverse and many more active regions will appear.
FURTHER : Black hole 33,000,000,000 times the size of the Sun, discovered by scientists
FURTHER : Another solar storm will arrive this weekend with possible aurora sightings
