Solar Weather

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When you hear the word “weather,” you probably think of clouds and lightning bolts and rainstorms. Maybe, if you live in particularly high elevation or latitude, you think snowstorms or even blizzards.

We humans are used to these weather patterns. They’re the norm here on Earth. But would you be surprised to hear that the sun has weather of its own?

The sun doesn’t have clouds. Electricity doesn’t crackle through its atmosphere and build up as lightning. Its surface sits comfortably at about 5800 K, which is 9980°F and 5526°C—so it doesn’t even get close to cold enough for rain or snow.

So what kind of weather does the sun have? Continue reading

The Sun’s Magnetic Show

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Do you recognize the name Galileo Galilei?

Galileo was the classical astronomer who made the drawing above. I have little idea what his writing actually says—it’s in Latin—but it’s clear enough what this early diagram is all about.

It’s a drawing of his observations of the sun.

And it’s proof, discovered way back in Galileo’s time but not accepted until much later, that the sun actually rotates.

How do we know that? Continue reading

Spots on the Sun

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Have you ever looked at the sun, and seen something like this?

Now, before you decide to look at it right now and see what you see, it’s my responsibility as an amateur astronomer to remind you of the safety risks. Focusing your eyes on the sun is dangerous—there’s a reason our eyes automatically flinch away.

How dangerous, you ask? Dangerous enough to burn and even scar your retinas, permanently damaging or even destroying your vision.

Yes, I’m serious.

Now, all this is not to turn you off solar observing entirely. There are safe—and cheap—ways to look at the sun, and see its spots.

But what exactly are sunspots?

Continue reading

Our Sun: The Corona

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When we observe our sun’s corona, we discover something odd.

It’s really, really hot.

But…wait a second. How is that odd? Shouldn’t the sun be hot?

Well…yes. It should, and it is. Its surface temperature is almost ten thousand degrees Fahrenheit, and its core is many times hotter. But there’s a basic law of physics that says energy flows from hotter regions to cooler regions.

The core and photosphere (the visible surface) follow this rule. Even the chromosphere, the lower atmosphere, does as it’s told. But the corona is made up of gases that are hotter than the chromosphere.

What’s up with that? Continue reading