# Solar Prominence (DD-038)

> A solar prominence is a huge loop of relatively cool, dense plasma (electrically charged hydrogen and helium) hanging in the sun's million-degree corona. Twisted magnetic fields rooted in the photosphere hold it up. Prominences form in about a day and can sit quietly for months, looping hundreds of thousands of miles above the surface. When the magnetic structure becomes unstable, the prominence erupts and usually becomes the bright core of a coronal mass ejection (CME). CMEs can carry billions of tons of material at speeds from under 250 km/s to nearly 3,000 km/s, and the fastest Earth-directed ones arrive in 15 to 18 hours.

- Department: Space (also Science)
- First published: 2025-09-07
- Last updated: 2025-09-07
- Permalink: https://detailenjoyer.com/case/solar-prominence/
- Original Reel title: Solar Prominent
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-038-F01**: Solar prominences are cool, dense loops of plasma held up in the sun's hot corona by twisted magnetic fields. Stable ones can last for months. _(Write-up · Exhibit B (Held up by magnetism))_
- **DD-038-F02**: When a prominence erupts it becomes the bright core of a coronal mass ejection, which can reach Earth in as little as 15 to 18 hours. _(Write-up · Exhibit E (From eruption to CME))_

## Write-up

Magnetic fields hold rivers of plasma above the sun. When a prominence erupts, it can ride out on a billion-ton CME.

1. **What a prominence is**: A prominence is a large, bright loop of plasma (electrically charged hydrogen and helium) extending from the sun's surface into the corona. Seen against the solar disk instead of the sky, it's called a filament.
2. **Held up by magnetism**: Prominences are anchored in the photosphere. Their plasma flows along a tangled, twisted magnetic structure generated by the sun's internal dynamo.
3. **Cool knots in a hot corona**: Prominences are cool, dense threads suspended in a corona that is far hotter. Scientists are still debating how so much cool plasma ends up there; the chromosphere is the only plausible source.
4. **Long-lived and enormous**: A prominence forms over about a day. Stable ones can last for months and loop hundreds of thousands of miles into space.
5. **From eruption to CME**: When the magnetic structure becomes unstable, the prominence bursts outward. Eruptive prominences show up as the brightest part inside a CME, though they usually take up only a small part of its volume.
6. **Space weather**: CMEs can carry billions of tons of material at speeds from under 250 km/s to nearly 3,000 km/s. The fastest Earth-directed ones arrive in 15 to 18 hours; slower ones take several days.

## Related case files

- [Solar Sailing (DD-039)](https://detailenjoyer.com/case/solar-sailing/): The sun's light can push spacecraft too.
- [Stellar Birth (DD-037)](https://detailenjoyer.com/case/stellar-birth/): How stars like the sun are born.
- [Guizhou Solar (DD-032)](https://detailenjoyer.com/case/guizhou-solar/): The same sunlight, collected on Earth.
- [Neutron Spin (DD-058)](https://detailenjoyer.com/case/neutron-spin/): Another star's magnetism at work: pulsars beam radiation from near their magnetic poles.
- [Coronal Mass Ejection (DD-091)](https://detailenjoyer.com/case/coronal-mass-ejection/): I paired it with another eruption from the Sun's surface
- [Quasi-Stellar (DD-106)](https://detailenjoyer.com/case/quasi-stellar/): I paired it with energy from our own star
- [(Z) Pinch Me (DD-741)](https://detailenjoyer.com/case/z-pinch-me/): Plasma shaped by magnetic fields, on the sun: loops of cool, dense plasma held up in the corona.

## Reel vs. record

- **Title**: the Reel's caption title 'Solar Prominent' is a truncation. Every caption is about solar prominences (0.6 s onward), so my title is 'Solar Prominence'. [frames]
- **Overstated**: prominences are described as 'arcs … that erupt from the sun's surface.' Most don't erupt. They form over about a day and can hang stably in the corona for months; only eruptive prominences break free. [NASA; NASA NTRS]
- **Credit misplaced**: the prominence doesn't release 'billions of tons' on its own. That figure describes a whole CME, and an eruptive prominence is usually a small part of the CME's volume. [NOAA SWPC; Gopalswamy 2014]
- **Confirmed**: 'hundreds of kilometers per second' is typical. CMEs range from under 250 km/s to nearly 3,000 km/s, and the fastest can reach Earth in 15 to 18 hours. [NOAA SWPC; Gopalswamy 2014]
- **Confirmed**: prominences are anchored in the photosphere and extend into the corona along magnetic fields. ('Corona' shouldn't be capitalized.) [NASA]

## Video: Solar Prominence: Magnetic Fields Hold Rivers of Plasma Above the Sun

- Duration: 22.2 s · Published: 2025-09-07
- File: https://detailenjoyer.com/assets/videos/DOTxunhkbJX.mp4

### Transcript

DID YOU KNOW? Solar prominences are gigantic arcs of glowing plasma that erupt from the sun's surface, anchored to the photosphere by strong magnetic fields and looping far into the Corona. When they break free, these so-called "eruptive" prominences release billions of tons of charged particles into space, often at speeds of hundreds of kilometers per second, forming coronal mass ejections that can travel toward Earth. NOW YOU KNOW!

## Questions & answers

**Q: What is a solar prominence called when it's seen against the face of the sun?**  
A: It's the same structure. Against the bright disk it looks like a dark thread. _(Source: Write-up · Exhibit A (What a prominence is) · What is a solar prominence? (NASA, 2015))_

**Q: What holds a prominence up above the sun's surface?**  
A: Prominence plasma flows along twisted magnetic structures anchored in the photosphere. _(Source: Write-up · Exhibit B (Held up by magnetism) · What is a solar prominence? (NASA, 2015); Prominences: The Key to Understanding Solar Activity (NASA Technical Reports Server))_

**Q: How long can a stable prominence last?**  
A: Prominences form in about a day, and stable ones can persist for months. _(Source: Write-up · Exhibit D (Long-lived and enormous) · What is a solar prominence? (NASA, 2015))_

**Q: What can an eruptive prominence become part of?**  
A: Eruptive prominences show up as the bright core of CMEs. _(Source: Write-up · Exhibit E (From eruption to CME) · What is a solar prominence? (NASA, 2015); Gopalswamy, 'Eruptive Prominences and CMEs', in Solar Prominences (Springer, 2014; NASA CDAW preprint); NASA's Heliophysics Fleet Captures May 1, 2013 Prominence Eruption and CME (NASA SVS))_

**Q: How fast can the fastest Earth-directed CMEs reach Earth?**  
A: The fastest travel at nearly 3,000 km/s, according to NOAA. _(Source: Write-up · Exhibit F (Space weather) · Coronal Mass Ejections (NOAA Space Weather Prediction Center))_

## Sources

- [What is a solar prominence? (NASA, 2015)](https://www.nasa.gov/image-article/what-solar-prominence/)
- [Coronal Mass Ejections (NOAA Space Weather Prediction Center)](https://www.swpc.noaa.gov/phenomena/Coronal-mass-ejections)
- [Prominences: The Key to Understanding Solar Activity (NASA Technical Reports Server)](https://ntrs.nasa.gov/api/citations/20110013276/downloads/20110013276.pdf)
- [Gopalswamy, 'Eruptive Prominences and CMEs', in Solar Prominences (Springer, 2014; NASA CDAW preprint)](https://cdaw.gsfc.nasa.gov/publications/gopal/gopal2014SolarProminence_chap15.pdf)
- [NASA's Heliophysics Fleet Captures May 1, 2013 Prominence Eruption and CME (NASA SVS)](https://svs.gsfc.nasa.gov/10785/)

## Cite this case file

Easterling, Marcus. "Solar Prominence." The Detail Department (DetailEnjoyer), case file DD-038, last updated Sep 7, 2025. https://detailenjoyer.com/case/solar-prominence/