- $4 is slamming Earth with solar flares and high-speed eruptions of plasma.
- Rarer events are picking up too, like a $4, $4, and a sun tornado.
From Earth, $4 may appear calm and quiet. But up close it's a turbulent nightmare.
$4 A growing number of flares, eruptions, giant plasma arcs, and vast "holes" have been bursting from its surface, some of which are pointed at Earth.
That's because the sun is building to the peak of its 11-year cycle. Forecasters expected the peak, called $4. But the explosion of solar activity in recent months suggests that $4, by the end of 2023.
While these $4 aren't immediately harmful to humans on Earth, they do pose a threat to satellites and certain tech on the ground like power grids.
That's why NASA has multiple observatories keeping a close eye on the sun to help understand and better anticipate its many different types of violent outbursts — some of which are many times $4 and are a stunning sight to behold.
Check out some of the different types below.
Solar flares can have the power of 1 billion hydrogen bombs
The sun is a ball of boiling gas and plasma, comprised of ultrahot charged particles. Their movement creates magnetic fields.
As the sun rotates, its magnetic fields can get contorted and tangled, building tension, until they explosively snap back into place like rubber bands.
The release of that energy can cause a powerful burst of light and radiation — a $4.
Flares are classified by their strength, from the weakest B class, then C, M, and X. The most powerful X flares have the energy equivalent of one billion hydrogen bombs, which is enough to power the whole world for 20,000 years, according to $4.
As the sun builds toward its maximum, solar flares, like X flares, will likely become more frequent.
Coronal mass ejections, aka high-speed space plasma
Sometimes solar flares occur alongside a coronal mass ejection (CME). That's a high-velocity eruption of plasma with embedded magnetic fields bursting from the sun's outer layer, the corona.
NASA and the European Space Agency captured footage of a CME shooting out from the sun and traveling through space, using their Solar Orbiter spacecraft, in the below video.
CMEs are common culprits of solar storms on Earth, since they can send a powerful flood of solar particles washing over the planet.
That supercharges the normal stream of charged particles that the sun is always sending toward us, called the solar wind.
$4 have knocked out power grids, silenced radio signals, pushed satellites out of orbit, disarmed GPS, and even damaged technology on the space station.
The fastest CMEs can reach Earth in just 15 hours, while others can take days to get here.
Coronal holes open a highway for solar wind
$4, but they're areas of the corona that are cooler in temperature, so they don't glow as bright as the rest of the sun. That makes them look black, like a deep hole, in images.
Because the coronal hole is lower in temperature, it's less dense. That lets the magnetic field lines straighten out and point directly into space, which allows the solar wind to flow out freely and quickly.
That's not usually enough to create a solar storm on Earth by itself, but when combined with a CME it can give the solar wind a powerful boost. That's what $4 in March.
Filaments, including a recent sun tornado and a solar polar vortex
When magnetic field lines arc out into space, filaments of solar material often anchor them to the sun's surface until they become unstable. At that point, the filament either falls back to the sun or erupts into space.
One recent swirling filament on the sun grew to the height of 14 Earths and earned itself the tornado nickname.
"A filament is a huge, twisted magnetic stricture that sits above the sun's surface, sometimes for months," Mathew Owens, a professor of space physics at the University of Reading, $4 after the tornado filament appeared in March.
The magnetic fields creating the tornado are invisible. The twister we see is the material anchoring those fields to the solar surface.
In February, a different giant filament of $4 appeared to break away from the sun and swirl around its north pole — like a polar vortex. Here's what it looked like:
Scott McIntosh, a solar physicist and deputy director of the National Center for Atmospheric Research, told $4 that a solar prominence appears in the same spot — at 55 degrees latitude — during every 11-year solar cycle.
It's probably related to the sun's magnetic field reversing every solar cycle, he said, but the exact mechanism causing it is a mystery.
This post has been updated with new information. It was originally published on May 5, 2023.