How to Safely View a Total Solar Eclipse

March 26, 2024March 27, 2024 / Emma / 5 Comments

Did you know that a total solar eclipse is coming up on April 8, 2024?

This one is primarily visible from North America; you can find more information about where to see it (and if it’ll be visible from your location) over here on TimeAndDate.com.

I was planning to travel to “totality” myself, but those plans fell through because I couldn’t get the time off work. Nevertheless, I’ll be helping out at a viewing event up north of Joshua Tree National Park!

In this post, I’ll take you through what you’ll see during a total solar eclipse–and, at each phase, I’ll let you know exactly how to safely view the sun!

(Later this week, we’ll be back to our regularly scheduled programming on active galaxies.)

Important: Always use solar glasses and solar filters that conform to the safety standard ISO 12312-2. Be careful! There are bad actors on the market that print this standard on unsafe equipment. Use this list of trustworthy suppliers from the American Astronomical Society.

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What is a Solar Eclipse?

March 26, 2024March 27, 2024 / Emma / 18 Comments

This post has been updated and republished from Sept 2017.

A solar eclipse is the most amazing astronomical sight you’ll ever see.

Not only is it the only time you’ll ever be able to clearly see the “new moon” phase of the moon, it’s the only time you’ll ever see the sun’s corona. And it’s the only time that, under very specific circumstances, you can actually look directly at the sun for a few moments.

But it’s not just an astronomical event. It’s an experience. You can see the moon’s shadow rushing toward you. Nature falls silent. It’s night during the day.

And there’s one coming up on April 8, 2024.

So, let me tell you a bit about what’s happening in the sky—and give you a few important safety warnings!

(If you’re wondering what happened to our unit on active galaxies, not to worry–I’m still publishing the next post this week!)

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The Annular Eclipse

October 4, 2023October 4, 2023 / Emma / 7 Comments

An annular solar eclipse is…an interesting sight, to say the least.

(I sincerely hope the photographer didn’t fry his camera taking this picture. Enough light from the sun is still reaching us to fry your retina, or damage your optics…)

The annular eclipse is not to be confused with an annual eclipse. When my dad first got excited about it back in 2012, preparing us for the spectacular sight of a solar eclipse in May, I wondered why the heck we hadn’t done this every year before. I’d just never heard the word “annular” before!

Since there’s an annular solar eclipse coming up in just over a week, I thought I’d touch up this post from back in 2017! (Don’t worry–we will soon be back to our “regularly scheduled programming” on galaxies.)

So…what exactly is an annular solar eclipse?

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What Causes the Lunar Phases?

March 7, 2018November 23, 2022 / Emma / Leave a comment

all-phases-of-the-moon-on-a-clear-dark-sky-516059951-59f0f494685fbe0011fc0523.jpg

We see it almost every night of our lives. For thousands of years, the greatest philosophers and astronomers alike have watched its face change and wondered why.

Step outside and observe the moon every day for a month and you will notice something fascinating. Over the course of the entire month, the moon will go through an entire cycle of phases—no more, no less.

But why?

The phases of the moon are something I’ve talked about before, but I wanted to spend some time on a few common misconceptions this time around and show you the truth behind the lunar phases.

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Einstein: General Relativity

September 27, 2017November 23, 2022 / Emma / Leave a comment

Albert Einstein may have been the genius among physicists, but like all others before his time, he stood on the shoulders of giants.

Einstein did not propose that the sun was the center of the solar system; that idea was already widely accepted when he came around. He didn’t discover elliptical orbits; that distinction belongs with Johannes Kepler.

But Kepler never could figure out why planets orbit the sun in ellipses instead of circles. Even Isaac Newton, who at last identified gravity as the reason we stick to Earth’s surface, couldn’t explain what gravity was—only how it worked.

Einstein provided that explanation with his general theory of relativity.

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Moving with the Tides

September 25, 2017November 23, 2022 / Emma / 13 Comments

Have you ever been to the beach?

If you’re from California like me, then I’m betting you have. If you’re from a place that’s not near an ocean and you’ve never been near the water all your life, then I’ll tell you a little bit about the tides.

They happen every day, twice a day. If you find yourself a nice comfortable spot overlooking the beach, you can see the waves come into the shore and then gently roll out again. If you stay for hours on end, you’ll see the water level eventually rise a bit.

And if you stay even longer, you’ll see the water level lower back down. When it’s high, it’s called high tide, and when it’s low, it’s called low tide.

The tides are partially responsible for the myth that the moon’s gravity affects you in some kind of metaphysical way. But this isn’t true at all.

So why do the tides happen?

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How Orbits Work

September 24, 2017November 23, 2022 / Emma / 14 Comments

Since Aristotle’s time over 2000 years ago, we have accepted that the moon orbits the Earth. We didn’t always know why, and we didn’t always accept this for the right reasons.

We used to assume that it happened just because we saw the moon move across the sky, and we believed the Earth to be the center of all motion in the solar system. But even when we realized—in the 1540s CE—that the sun was in fact the center of the solar system, the moon kept its place around the Earth.

And rightfully so. Astronomers now know that the moon orbits the Earth based on scientific observation, rather than the “logical” guesses of Aristotle’s time. And we even know why it orbits—gravity, the one force in all the universe we can’t escape.

But I can tell you, the moon’s orbit isn’t a perfect circle, and if gravity were the only reason it orbited, it would crash straight into the Earth. After all, people stay grounded on Earth’s surface because of gravity, and we don’t orbit our planet, do we?

So how does the moon orbit the Earth? For that matter, how does any satellite?

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Newton and Gravity

September 23, 2017November 23, 2022 / Emma / 4 Comments

So, the moon stays in orbit around the Earth, right?

Yeah, I thought so. But why? The moon’s orbit is not a straight line, which means it’s accelerated motion (using the physics definition, which is absolutely any change in speed or direction).

And in order for acceleration to happen, according to Newton’s first law of motion, a force has to happen—meaning, something has to reach out, touch the moon, and drag it into orbit around Earth.

Well, that doesn’t happen, last I checked. I mean, it’s not like we have some kind of giant cord connecting us to the moon. How crazy would that be?

So why does the moon orbit the Earth?

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Galileo and the Telescope

September 20, 2017November 23, 2022 / Emma / Leave a comment

When you hear the name “Galileo Galilei,” what immediately comes to mind?

If you thought, “inventor of the telescope,” you’re not alone. I also wouldn’t be surprised if you thought “condemned by the Inquisition for believing the Earth orbited the sun.”

But neither of these are true. If you’ve been following my more recent astronomy posts, you probably realize why—in Galileo’s time, people already knew that the Earth moved around the sun.

The idea that he invented the telescope is more understandable…but, again, it’s not true.

So what is true about Galileo, and how did he contribute to our understanding of astronomy?

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Archaeoastronomy

September 13, 2017November 23, 2022 / Emma / 7 Comments

Imagine that you’re living sometime around 2000 BCE, give or take a thousand years or so. That’s about 4000 years before our time.

You look up at the sky at night, and see it filled with numerous points of light. Some of them stay mostly fixed, but move mysteriously in circles around the north pole. Others move with the rest, but wander a bit from time to time.

And then there’s the sun, whose brilliant rays light the day. The moon, like the sun, doesn’t seem to follow the path of the lights in the sky. It even changes its shape, and sometimes disappears entirely.

Wouldn’t you wonder if there was some pattern to these otherworldly motions? Wouldn’t you devote time to studying them and seeing if you could predict them?

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