Space, Sun, and Solar Viewing: Facts versus Fiction

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When it comes to Earth’s relationship to the sun, a great deal of mystery and misconception abound in our little spot in the solar system. In advance of the upcoming North American Eclipse, happening on August 21, 2017, I’m here to demystify and debunk the fiction and present the facts to get you on solid footing and, hopefully, spark some interest in getting out there and looking up at the sky and into space.

It’s unsafe to look at the sun during an eclipse.

TRUE and FALSE  This one is a lot of fact and a little fiction. The fiction is that if you’re right in the path of totality (where you’ll see the complete eclipse), then during the brief period of total coverage, it is safe to look at the sun without eye protection. Totality usually only lasts a few moments, so don’t dawdle. The fact is that at ANY TIME before or after totality—the times of partial eclipse—you absolutely MUST wear eye protection or serious damage can occur, up to and including blindness.

The sun is yellow.

TRUE… kind of  Obviously a fact, right? To paraphrase a wise old knight from a film series about a far-off galaxy, it’s true… from a certain point of view. The sun is all colors, or what we call “white.” We perceive all the colors of the visible spectrum (remember ROYGBIV from elementary school?) as the color white. We can see this demonstrated in a rainbow—water vapor in the atmosphere act as prisms and separates the colors. At sunrise and sunset, when the sun is low on the horizon, it appears to be yellow-orange because the shorter wavelengths (GBIV) are scattered by our atmosphere, allowing just the longer wavelengths (ROY) through for us to see.

BONUS FACT  The sun emits a massive amount of radiation beyond the light that we can see. If you could detect wavelengths outside of our limited visible spectrum, like ultraviolet and infrared, the sun would look completely different. Not only can certain instruments detect these wavelengths, but many animals and insects can, as well, so your pet dog and iguana will probably think the sun is a different color than what you and I do.

Solar eclipses happen at night.

FALSE  A solar eclipse occurs when the moon aligns perfectly between the sun and Earth, blocking the sun’s light from shining on a portion of the Earth’s surface, so this is fiction. A solar eclipse, whether total, partial, or any kind of annular, can only happen during the day.

The sun is massive.

TRUE  One of the facts that I find absolutely mind-blowing is that the sun accounts for more than 99.8% of all the mass in our solar system. Think about that for a second. All the planets and all their moons in our solar system, all together, represent just 0.2% of all the mass in it.

BONUS FACT Size-wise, it’s about 109 times the diameter of the Earth, and has a volume so massive that about one million Earths would fit inside it. The sun’s big, is what I’m saying.

The moon gives off its own light.

FALSE  The moon is only visible because of the sun. The thin atmosphere and gray color make the moon essentially an enormous reflector for the sun’s light.

The sun is on fire.

FALSE  Despite its representation in pop culture and art, the sun isn’t on fire. The sun is a big ball of gas—mostly nitrogen gas. The light and heat produced by the sun come from a nuclear fusion reaction when two hydrogen atoms combine to form helium. While it might appear as a ball of fire, it’s really a chaotic ball of uncontrolled nuclear radiation.

Sunspots are storms on the surface of the sun.

FALSE  The sun has no true surface or atmosphere, so there can’t really be “storms” in the sense that we’re used to them on Earth. A sunspot is a cooler (and inactive) region of the photosphere. The nuclear reaction that produces heat and light occurs toward the sun’s core. The heat, light, and radiation rise to the outer layer, called the photosphere, and are released into space through convection currents flowing upward and downward from the core to the photosphere, in and endless cycle. The cooler regions appear darker against the bright light of the active (hot) regions. Because of the fluidity caused by the constant cooling at the surface and heating in the core, a sunspot can appear to move and can grow larger or smaller hourly.

Copernicus first postulated that the sun was the center of the solar system.

FALSE  Many of us were taught that in the 15th Century, Nicolaus Copernicus originated the idea of a heliocentric solar system (where the sun is at the center and everything orbits it), as opposed to a geocentric one (where the Earth is at the center). In fact, it was a Greek named Heracleides who proposed such a model of the solar system, some eighteen to nineteen centuries earlier. Copernicus’s contribution was devising the math and running the numbers, assuming a heliocentric solar system, that finally made the motion of the planets and other heavenly bodies make sense.

BONUS FACT  Johannes Kepler refined the Copernican model by using elliptical orbits (instead of circular) and was able to predict observable occurrences accurately, thereby proving Copernicus’s theory.  

BONUS FACT  A 2012 survey by the National Science Foundation indicates that 26% of Americans surveyed believe that the sun orbits the earth—not the other way around. A similar poll, in 2005, found that 66% of European Union members did not acknowledge the heliocentric solar system.

A “light year” is a measure of time.

FALSE  It’s a measure of distance. Light travels at 186,282 miles per second, or 299,792 kilometers per second, so a light year is the distance that a photon of light will travel in a year… which is 6 TRILLION miles.

Light travels so fast that we perceive everything instantaneously.

FALSE  The truth is that we all live in the past. Literally. Everything we see around us is visible because light bounces off it and hits our eyes. On earth, because of how fast light travels, that amount of time is nanoseconds so we perceive it as instantaneous—but when you’re talking astronomical distances, it becomes much more apparent. When a photon of light leaves the sun, it takes a little over 8 minutes to reach the Earth. Which means during the day, we’re always on an 8-minute delay.

BONUS FACTS

• Light reflected from the surface of the moon takes about a second to reach us.

• Light from the next closest star, Alpha Centauri, takes more than 4 years to reach the Earth.

• The galaxies and other deep space objects that we see are millions of light years away, so when you look at a galaxy through a telescope in your backyard, the light that is reaching your eye is already millions of years old.

When the sun reaches the end of its life, it’s going to explode and obliterate the Earth.

FALSE  But the truth isn’t very reassuring. The sun is slowly heating up as it ages, growing at a rate of about 10% every billion years. So instead of blowing up in spectacular style, it will slowly increase its heat and radiation output until it slowly burns all the water, air, and atmosphere off the Earth, causing a world-wide extermination of all life. But the good news is that it’s going to take a billion years, so there’s that.

Well, this piece has taken a turn for the depressing, hasn’t it? I was going to end this article with that, but it was such a downer that I couldn’t do that to you, dear reader.

The sun can affect or disrupt communication, TV broadcasts, and even the Internet.

TRUE  This is a big ole fact, and it happens frequently enough that we have a name for it: a “sun outage.” (Because the guy in charge of naming things was apparently off that day.) A sun outage happens when the energy from the sun disrupts the signal from a satellite. All satellites can be affected, but geostationary satellites are particularly vulnerable. Geostationary means that the satellite orbits the Earth at the same speed and direction as the Earth’s rotation, to stay directly above the same spot at all times—and about 22,236 miles overhead.

The interference happens mostly during an equinox, when the sun traverses the equator, where many important geostationary satellites are “parked.” The problem is that many of the satellites transmit in the microwave frequency, and the sun also transmits those same frequencies. During an equinox, the sun lines up with the satellites and the Earth and causes a lot of background “noise,” so much, in fact, that receivers on Earth can’t read the actual satellite transmissions from the sun’s microwave output. While geostationary satellites are the most affected, just about any satellite can experience this same interference at just about any time.

This is different from a solar storm, which happens when the sun releases an enormous amount of energy during a period of intense activity, generally on a +/- 11-year cycle. These events release plasma and sub-atomic particles that, when they reach Earth, can disrupt or damage satellites. The main difference between a sun outage and a solar storm is that the former can briefly disrupt a signal, while the latter can damage or completely disable the entire satellite.

On the plus side, solar storms also produce beautiful auroras, for what that’s worth, when you can’t watch the Kardashian’s latest shenanigans and tweet angrily about it.

If you have any questions or comments, please post them in the designated section, below.

9 Comments

I plan to use my Canon Rebel.  Not planing to use any filters but will use tripod.  How will straight shooting effect the outcome? also I'd like to know how long does the eclipse actually last.  How much time do we have to shoot. I'll be in the Hudson Valley upstate New York. I haven't a clue how location will affect this and if in fact it even does.

I did a series on the moon in the freezing winter and got shots I couldn't believe.  Quite a learning experience.  I saved my finger by putting it in my warm moouth.  Had to go inside to warm up and also the cold affected the battery charge.  That was some February.

Do you have any advice for me since I'm not using filters?   Sincerely,Gail S. Goodman

You should use a filter!! Neutral Density...check with your photo store on which one. If you use ANY camera with no filter in place, it would only work to take a picture at the 100% eclipse, otherwise it will be washed out by the intense sunlight and might damage the sensor inside the camera. Do NOT look at the sun, not even through your SLR and lense, without a ND filter.

Good questions Gail...let's unpack this:

Absolutely use a filter. Shooting the sun straight will cause immense over-exposure. You're better off using dedicated solar filters (as opposed to ND filters), but you can get away with some of the eclipse or solar ND filters on our website, but there's a huge caveat: If your camera has an optical viewfinder DO NOT USE A NEUTRAL DENSITY FILTER. An ND filter only dims the intense bright white light from the sun...there is no protection against ultraviolet (UV) and infrared (IR) radiation. If you have an optical viewfinder you would be exposing your eye to dangerous levels of UV and IR radiation that can cause catastrophic eye damage - and since our eyes don't have pain receptors for radiation, you wouldn't know the damage is happening until it's too late. Only use an ND filter on cameras with a digital viewfinder or only when using the live-view feature on the rear display screen. If you don't know what kind of viewfinder you have, stick with an ISO 12312-2 certified filter that is safe for direct solar viewing - this will protect you from the intense white-light plus UV and IR radiation.

In upsate NY, you will be getting a partial ecipse with a max Obscuration of around 70% (meaning 70% of the sun will be eclipsed by the moon) - New York is far out of the path of Totality. The entire eclipse (starting with the first little 'bite' and running all the way through) will last about 2.5 hours - from about 1:20pm until 4pm, with the maximum eclipse happening at around 2:45pm. During those 2.5 hours you will have a variation of the percent of obscuration, so you'll need to adjust your setting periodically. Check out some of our companion articles on how to photograph the solar eclipse for some tips and tricks.

https://eclipse2017.nasa.gov/sites/default/files/interactive_map/index.html

https://www.bhphotovideo.com/explora/photography/features/solar-eclipse-photography-faq

https://www.bhphotovideo.com/explora/photography/tips-and-solutions/how-photograph-solar-eclipse

https://www.bhphotovideo.com/explora/photography/buying-guide/recommended-lenses-shooting-solar-eclipse-any-budget

https://www.bhphotovideo.com/explora/photography/tips-and-solutions/how-photograph-sun

The sun is mostly hydrogen with some helium.  It has almost no nitrogen.  You're confusing the composition of the sun and the composition of the earth's atmosphere.

Bill, you are 100% correct. That's was a typo and will be corrected as soon as possible. Thanks for pointing that out.

Truth is we have no idea what it's made of, nothing has ever taken a sample. Just like we have no idea what's really at the center of the earth.

Your understanding of helio-geo centric rotation is more than 100 years out of date.  I suggest you check out the Special Theory of Relativity (A. Einstein 1905) and the General Theory of Relativity (A. Einstein 1915).  

Neither the geocentric nor the heliocentric explanation is correct (according to Einstein).   

Sorry to break it to you, but the Earth goes around the sun.

You're correct Jim, but since this is a primer piece for the general public, the explanation provided is enought to get the point across - it's not a scholarly work for astro or theoretical physists.

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