Watch monster flare-spewing sunspot grow to be 15 times wider than Earth (video)

If there were a Page Six for what's going on in space, the sunspot region AR3664 would definitely be one of the biggest "stars" highlighted.

Over the past few days, the region has grown to be roughly 124,300 miles (200,000 kilometers) wide — more than 15 times the diameter of Earth. You can see this dramatic evolution in a new time-lapse video, which consists of imagery gathered by NASA's Solar Dynamics Observatory spacecraft.

And AR3664 is active as well as enormous: It keeps firing off powerful solar flares and coronal mass ejections (CMEs), some of which could hit Earth and ramp up our auroras this weekend.

Related: 4 large incoming solar bursts could supercharge the auroras this weekend 

Sunspots are dark patches on the solar surface where the magnetic field is abnormally strong — about 2,500 times stronger than that of Earth, according to the U.S. National Oceanic and Atmospheric Administration's (NOAA) National Weather Service. 

Sunspots typically are about the size of Earth, but some, like AR3664, can become even more gigantic. The larger the region gets, the bigger the increase in magnetic complexity and threat of additional solar flares.

And here's an interesting fact about AR3664: According to, it's currently about the same size as the sunspot linked to the Carrington event of 1859, the most powerful geomagnetic storm ever recorded on Earth.

The current forecast discussion from NOAA's Space Weather Prediction Center continues to keep an eye on the growing region to monitor for further activity. Scientists expect solar activity to stay elevated into Mother's Day weekend and suspect that AR3664 could erupt with more flares and CMEs.

And one more thing: AR3664 is so large that you might even be able to spot it without the aid of binoculars or a telescope. But be sure to use eye protection if you try — like the eclipse glasses you used to see last month's epic total solar eclipse.

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Meredith Garofalo
Contributing Writer

Meredith is a regional Murrow award-winning Certified Broadcast Meteorologist and science/space correspondent. She most recently was a Freelance Meteorologist for NY 1 in New York City & the 19 First Alert Weather Team in Cleveland. A self-described "Rocket Girl," Meredith's personal and professional work has drawn recognition over the last decade, including the inaugural Valparaiso University Alumni Association First Decade Achievement Award, two special reports in News 12's Climate Special "Saving Our Shores" that won a Regional Edward R. Murrow Award, multiple Fair Media Council Folio & Press Club of Long Island awards for meteorology & reporting, and a Long Island Business News & NYC TV Week "40 Under 40" Award.

  • rod
    I was able to view this monster sunspot region this morning.

    AR3664 is one big sunspot group and active region 🙂 Observed 0900-0945 EDT 11-May-2024. This was the Carrington sunspot active reported in the news, very large sunspot documented in 1859. I used 90-mm refractor with glass white light solar filter, TeleVue 40-mm and TeleVue 32-mm eyepiece for 25x to 31x views. Some cirrus did form slight obscruation layer but easy to see with many dark cores and other active region sunspots visible too. Weather mostly sunny, some cirrus, temperatue 14C, winds 340/4 knots, h=58%. Given the Sun's distance this morning AR3664 was reported to be near 200,000 km in diameter or about 4.5 arcminute angular size. Very cool to see this in my telescope views.