Astronomy Picture of the Day - AR 4478: Giant Sunspot Group

NASA ^ | 28 Jun, 2026 | Image Credit & Copyright: Alfredo Vidal Pérez

[MtnClimber]

Explanation: Right now, one of the largest sunspot groups in recent history is crossing the Sun. Active Region 4478 is not only big -- it's violent, showing tangled magnetic fields capable of throwing off huge clouds of particles into the Solar System. Some of these CMEs might impact the Earth. At the extreme, these solar storms could cause some Earth-orbiting satellites to malfunction, the Earth's atmosphere to slightly distort, and electrical power grids to surge. When impacting Earth's upper atmosphere, these particles can produce beautiful auroras. Pictured here, AR 4478 and its dark sunspots were captured in visible light a few days ago from Barcelona, Spain. Almost as large as AR 3664 was in 2024, the AR 4478 sunspot group is so big that it is visible just with glasses specially designed to view solar eclipses. This week, skygazing enthusiasts all over the globe will not only be tracking AR 4478 during the day -- but keenly watching night skies for its corresponding bright auroras.

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TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: apod; nasa; sunspots

[MtnClimber]

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For more detail go to the link and click on the image for a high definition image. You can then move the magnifying glass cursor then click to zoom in and click again to zoom out. When zoomed in you can scan by moving the side bars on the bottom and right side of the image.

[MtnClimber]

[MtnClimber]

Pinging the APOD list

🪐 🌟 🌌 🍔

[Diana in Wisconsin]

“Active Region 4478 is not only big — it’s violent, showing tangled magnetic fields capable of throwing off huge clouds of particles into the Solar System.”

And some people think MAN can control the weather! LOL!

Reminds me of Mom telling use girls not to touch the stove because it was HOT. A week would go by and I’d ask Mom if the stove was still hot, or counld I touch it now?

Little Sister would look Mom in the eye, slap her hands on the hot stove and say, ‘Oh, YEAH?’ LOL!

[Pocketdoor]

I told my 2-3 year old daughter don’t touch it’s hot. she immediately reached out and touched in burned herself. I wonder if there’s a personality trait in the different actions. lol

[BenLurkin]

Solar storms might not just dazzle the skies—they could help nudge vulnerable faults toward earthquakes.

February 24, 2026

Kyoto University

Summary:
Scientists have proposed a surprising connection between solar flares and earthquakes. When solar activity disturbs the ionosphere, it may generate electric fields that penetrate fragile fracture zones in Earth’s crust. If a fault is already critically stressed, this extra electrostatic pressure could help trigger a quake. The idea doesn’t claim direct causation, but it offers a fresh way to think about how space weather and seismic events might interact.

https://www.sciencedaily.com/releases/2026/02/260224023209.htm

[Diana in Wisconsin]

Oh, no doubt. Sis and I are like oil and water. Hard to believe we have the same parents. She claims to have had such an AWFUL childhood - I’m thinking she brought it on herself for the most part. ;)

[PeterPrinciple]

Reminds me of Mom telling use girls not to touch the stove because it was HOT. A week would go by and I’d ask Mom if the stove was still hot, or counld I touch it now?

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“We should be careful to get out of an experience only the wisdom that is in it and stop there lest we be like the cat that sits down on a hot stove lid. She will never sit down on a hot stove lid again and that is well but also she will never sit down on a cold one anymore.” Mark Twain

[No name given]

Wow.

[telescope115]

I observed this sunspot last week. I want to photograph it but I’m having trouble with my telescope’s tracking mount. It surely is quite a grouping of sunspots. Sometimes it hard to understand that each one of those sunspots is larger than the Earth.

[Red Badger]

Just think, each one of those sunspots are several times larger that the entire Earth.....................

[MtnClimber]

They have to be caused by global warming. If I go out and run my car do you think it will get larger?

[17th Miss Regt]

If I go out and run my car, do you think it will get larger?

That generally will not have that effect. However, if you run your car unnecessarily, it may increase the pay disparities between the workers and most CEOs.

[SkyDancer]

I bet you could drop Earth into one of those spots.

[Yardstick]

so big that it is visible just with glasses specially designed to view solar eclipses.
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8 light-minutes away yet still visible without magnification. That is a serious spot.

People are saying it’s the biggest spot ever, and possibly the best. /DJT voice

[Red Badger]

Only if you run the air conditioner...........

[Diana in Wisconsin]

Perfect. Learn from your mistakes. But as far as CATS go:

[Diana in Wisconsin]

“...each one of those sunspots is larger than the Earth.”

That’s gonna leave a MARK - but it’ll buff right out. ;)

[SunkenCiv]

Thanks!