Still Got Those Eclipse Glasses? Put Them Back On to See Huge Sunspots
If you didn't donate your eclipse glasses already, hold onto them for a little bit longer. Despite the name, the glasses can be used to look at the Sun anytime, and right now, you can use them to see some pretty amazing sunspots.
As Bob King of the astronomy blog Astro Bob writes, "Two large sunspot groups, regions 2673 and 2674, have made a beautiful mess of the Sun's otherwise smooth complexion." The latter has become one of the largest sunspots of the year.
Sunspots are areas of intense magnetic fields that appear dark against the surface of the Sun because they're cooler than the areas around them. Their presence is linked to space weather events like solar flares and coronal mass ejections. Their number waxes and wanes in roughly 11-year periods, and as astronomer Phil Plait tells Mental Floss, "we’re sliding into the minimum now." But that doesn't mean there are no sunspots. The longest period of time the Sun has gone without observable sunspots in the past few years was 15 days in March 2017.
This NASA video below shows the movement of a sunspot in July. That one was about 78,000 miles across—nearly 10 times the size of Earth.
Since sunspot sightings are on the downswing for now, this latest appearance is a good reason to get outside and stare at the Sun—with a few safety measures, of course. "These beauties just showed up a few days ago," Plait says. "Sunspots big enough to see with the naked eye are rare, but these are big enough to spot with proper protection."
Hopefully you didn't toss your eclipse glasses immediately after the August dalliance with totality, because there will be plenty of other solar events to look at before the next big solar eclipse in the U.S. in 2024. As always, we must remind you not to stare directly into the Sun, or at best, you'll probably see more spots than you bargained for. If you're not sure about the provenance of your eclipse glasses, make sure to check the certification listed on the temples.
[h/t Astro Bob and Phil Plait]