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kottke.org posts about 2017 solar eclipse

Solar eclipse myth busted: it’s perfectly safe for kids to be outside during an eclipse

posted by Jason Kottke   Aug 20, 2017

Throughout history, total solar eclipses have been unnerving. To ancient cultures, they signified bad omens, the apocalypse, or that the Sun was being eaten by a sky creature.

There were a tumult, and disorder. All were disquieted, unnerved, frightened. Then there was weeping. The commonfolk raised a cup, lifting their voices, making a great din, calling out shrieking. People of light complexion were slain as sacrifices; captives were killed. All offered their blood.

But even in modern times, a lack of scientific understanding of what happens during a solar eclipse can cause apprehension and panic. Until hearing the same story from two different people in the past week, I had no idea that during solar eclipses, it is routine for schoolchildren to be kept inside until the “danger” has passed. Charles Fulco, a NASA and AAS 2017 U.S. Eclipse Educator, is trying to allay these fears by addressing common eclipse misconceptions.

“The Sun is more dangerous during an eclipse.” This is utter nonsense and for some reason, has persisted into the 21st Century. An eclipsed Sun is no more dangerous than the “everyday” Sun, but for some reason, some districts still keep teachers and students in their rooms with pulled shades, watching the eclipse on a screen, rather than outdoors, safely and under the care of a professional educator. I believe their fear of nature is transferred to the students as well: If the adult says an eclipse is scary and dangerous, than it must be!

Phil Plait agrees:

As I make my final preparations for my eclipse travels (rural western Wyoming, if you’re curious) I’m hearing stories that are making me very unhappy: Some school districts across the country are telling children to stay inside during the eclipse, out of fear they’ll damage their eyes.

Let me be clear: Schools, administrators, teachers, parents: Don’t do this. YOU CAN LET THE KIDS SEE THE ECLIPSE. You just have to be safe about it.

I can appreciate the difficulty of telling 25 first graders there’s something cool happening with the Sun and then trying to get them not to look directly at it, but keeping kids inside is not the answer. For one thing, they’re missing out on a genuine celestial spectacle & learning opportunity and for another, you’re teaching people bad science. A friend, who is one of the smartest people I know, was genuinely concerned for her kids’ safety during the eclipse because when she was a kid, she was kept inside a classroom with the shades drawn because, she was told, it was dangerous for them to be outside. Dangerous to be outside in the sunshine! A clear case of educators doing the exact opposite of what they should be doing.

A simulated “play-by-play” of a total eclipse

posted by Jason Kottke   Aug 20, 2017

This video from the Weather Channel is pretty neat and useful: a play-by-play of what to expect during the eclipse, from being able to see Venus in broad daylight to animals possibly acting weird to the 360-degree “sunset” that happens about 2 minutes before totality.

Viewing a total solar eclipse from an airplane

posted by Jason Kottke   Aug 18, 2017

On March 8-9, 2016, a total solar eclipse swept across the Pacific Ocean for more than 5 hours. About a year before the eclipse, Hayden Planetarium astronomer Joe Rao realized Alaska Airlines flight 870 from Anchorage to Honolulu would pass right through the path of totality…but 25 minutes too early. Rao called the airline and convinced them to shift the flight time.

Alaska’s fleet director, Captain Brian Holm, reviewed the proposed flight path and possible in-route changes to optimize for the eclipse. The schedule planning team pushed back the departure time by 25 minutes, to 2 p.m.

On the day of the flight, Dispatch will develop the specific flight plan, to find the most efficient route and account for weather and wind. Maintenance and maintenance control will help make sure the plane is ready to go — they even washed all the windows on the right side of the plane.

Captain Hal Andersen also coordinated with Oceanic Air Traffic Control, to make them aware that the flight might require a few more tactical changes then normal.

“The key to success here is meeting some very tight time constraints — specific latitudes and longitudes over the ocean,” Andersen said. “With the flight management computer, it’s a pretty easy challenge, but it’s something we need to pay very close attention to. We don’t want to be too far ahead or too far behind schedule.”

The video was shot by a very excited Mike Kentrianakis of the American Astronomical Society, who has witnessed 20 solar eclipses during his lifetime.

July 11, 2010. That was the eclipse over Easter Island, the one for which hotel room rates were so high that there was no way Kentrianakis could afford it. Instead, he considered attempting a trip to Argentina, where experts predicted there was a 5 percent chance of clear skies. His wife at the time, Olga, urged him not to go — it’s not worth the expense, she insisted. Reluctantly, Kentrianakis stayed home.

“It was the beginning of the end for us,” Kentrianakis says. There were problems in the marriage before that episode, “but it affected me that I felt that she didn’t really appreciate what I loved.” They were divorced the following year.

Kentrianakis doesn’t like to dwell on this, or the other things he’s given up to chase eclipses. He knows his bosses grumbled about the missed days of work. Friends raise their eyebrows at the extremes to which he goes. He’s unwilling to admit how much he’s spent on his obsession.

“There is a trade-off for everything, for what somebody wants,” he says.

A camera on the Deep Space Climate Observatory satellite captured the eclipse’s shadow as it moved across the Earth:

For this year’s eclipse, Alaska Airlines is doing a special charter flight for astronomy nerds and eclipse chasers. Depending on how this eclipse goes, seeing an eclipse from an airplane might be on my bucket list for next time. (via @coudal)

How to predict total solar eclipses

posted by Jason Kottke   Aug 18, 2017

The Exploratorium in San Francisco has produced a great explainer video about the science of predicting total solar eclipses. Each eclipse belongs to a repeating series of eclipses called a Saros cycle that repeats every 18 years 11 days and 8 hours.

Saros 145

There are now 40 active Saros cycles and the August 2017 eclipse belongs to Saros 145, which produced its first total eclipse in June 1909 and will produce its last total eclipse in September 2648.

A tour of our solar system’s eclipses

posted by Jason Kottke   Aug 16, 2017

In a meditative video for the NY Times, Dennis Overbye takes us on a tour of eclipses that happen in our solar system and beyond.

On the 21st day of August, 2017, the moon will slide between the Earth and the sun, painting a swath of darkness across North America. The Great American Solar Eclipse. An exercise in cosmic geometry. A reminder that we live on one sphere among many, all moving to the laws of Kepler, Newton and Einstein.

Humans have many more vantage points from which to observe solar eclipses than when the last solar eclipse occurred in the US in 1979. I had no idea that the Mars rovers had caught partial solar eclipses on Mars…so cool. (via @jossfong)

Solar eclipse searches match the path of totality

posted by Jason Kottke   Aug 15, 2017

Solar Eclipse Searches

According to Google Trends, search traffic about the upcoming solar eclipse mirrors the path of totality. And according to XKCD, pre-eclipse search traffic for “eclipse” is outpacing pre-election search traffic for “election”.

Why is the upcoming total solar eclipse such a big deal?

posted by Jason Kottke   Jul 20, 2017

Well, the short answer is that they don’t happen all that often and when they do, they’ve visible from only a small bit of Earth. Joss Fong elaborates in a video for Vox.

The next total solar eclipse to visit the US will be in 2024. If an eclipse happens to come to your town, you’re lucky. Any given location will see a total solar eclipse only once in more than 300 years, on average. The vast majority of us will have to travel to an eclipse path if we want to see a total eclipse in our lifetimes.

I’m off to Nebraska in August to meet up with some friends and see the eclipse. (And that 2024 eclipse Fong mentions? The path of totality goes right over my damn house. Woooo!) But no matter where you are in North America, you can enjoy the eclipse…just make sure you buy some safety glasses (and other supplies) if you want to look directly at the Sun. (via @veganstraightedge)

How to safely enjoy the 2017 solar eclipse, a buyer’s guide for normal people

posted by Jason Kottke   Jul 12, 2017

Solar Eclipse Illo

Important update: Since I published this guide a month ago, NASA and the AAS have updated their recommendation on buying solar safety glasses due to reports of counterfeit eclipse glasses. They no longer recommend looking for the ISO rating alone but only buying from a recommended manufacturer. If you have purchased glasses or are going to purchase glasses, read this page carefully before using them, paying particular attention to this bit:

Unfortunately, you can’t check whether a filter meets the ISO standard yourself — doing so requires a specialized and expensive piece of laboratory equipment called a spectrophotometer that shines intense UV, visible, and IR light through the filter and measures how much gets through at each wavelength. Solar filter manufacturers send their products to specialized labs that are accredited to perform the tests necessary to verify compliance with the ISO 12312-2 safety specifications. Once they have the paperwork that documents their products as ISO-compliant, they can legitimately use the ISO logo on their products and packaging.

Even more unfortunately, unscrupulous vendors can grab the ISO logo off the internet and put it on their products and packaging even if their eclipse glasses or viewers haven’t been properly tested. This means that just seeing the ISO logo or a label claiming ISO 12312-2 certification isn’t good enough. You need to know that the product comes from a reputable manufacturer or one of their authorized dealers.

Amazon recently sent out emails to the buyers of the plastic-framed glasses I bought and linked to here (“habibee 4-Pack Black Plastic Eclipse Glasses CE & ISO Certified 2017 Safe Solar Eclipses Viewing Shades Block Sun Ultraviolet UV Lights Goggles”), saying that they have “not received confirmation from the supplier of your order that they sourced the item from a recommended manufacturer” and, to their credit, have automatically issued refunds to those buyers. They also appear to have removed any products from their site that aren’t sourced from a recommended manufacturer. This doesn’t necessarily mean the glasses are faulty…it just means the solar filter paper used for the lenses can’t be sourced. Again, read this page carefully before deciding to use any glasses you may have purchased. I tested a pair this morning, looking at bright light bulbs and they seem appropriately dark, but as noted by the AAS, who knows about the UV and IR filtering? I’m throwing mine out.

The cardboard-framed glasses I linked to (while currently sold out) are manufactured by American Paper Optics, which is on the AAS’s list of reputable vendors. Also on the list is the manufacturer of the solar filter sheets, Thousand Oaks Optical. The two cardboard camera lens covers I linked to have been deleted from Amazon, a sign that their sourcing cannot be verified. I’ve updated the links and text below to only include links to products on the list of reputable vendors. Most are sold out at this point anyway, so…

I wish I’d had these new NASA and AAS recommendations a month ago…I obviously would have followed them closely in making buying choices & recommendations. That some unscrupulous manufacturers are using people’s enthusiasm for science and viewing the eclipse to sell potentially harmful products makes me angry and sick to my stomach. Luckily Amazon is doing the right thing here with refunds and safety notices. And thanks to NASA and the AAS for their guidance…again please read this before using your eclipse glasses, even ones you may have gotten free from your public library or through other organizations. /end update

On August 21, 2017 across the entire United States, the Moon will move in front of the Sun, partially blocking it from our view. For those on the path of totality, the Moon will entirely block out the Sun for more than 2 minutes. I’ve been looking forward to seeing a total solar eclipse since I was a little kid, so I’ve been doing a lot of research on what to buy to enjoy the eclipse safely. Here’s what I’ve come up with.

I’ve oriented this guide toward the enthusiastic beginner, someone who’s excited about experiencing the wonder of the eclipse with their friends & family but isn’t interested in expensive specialty gear or photography (like me!). And, again, since you will be able to see this eclipse from everywhere in North America to some degree, this guide applies to anyone in the US/Canada/Mexico.

In planning for eclipse viewing, please check out NASA’s safety notes for more information. Make sure that whatever you buy, it’s properly rated for naked eye solar viewing. Looking directly at the Sun without a proper filter can cause permanent damage, particularly through binoculars, a camera lens, or a telescope.

Note: If you’re going to get eclipse supplies, now is the time. Some of this stuff will probably be very difficult to find (or very expensive) as we approach August 21 — for instance, shipping estimates on Amazon for some of the glasses are mid-August already.

Solar eclipse glasses are essential. Right up until the Sun goes completely behind the Moon (if you’re on the path of totality), you will want to look at the crescent-shaped Sun and you’ll need certified safety glasses to do so. Regular sunglasses will not work! Do not even. There are several options…find some in stock that ship soon. Note: If you have young kids, splurge for the plastic framed glasses (if you can find them…most are sold out now)…my testing indicates the cardboard ones don’t stay on smaller heads as well.

Make a pinhole viewer. A pinhole viewer will let you see the shape of the eclipsed Sun without having to look directly at it. This Exploratorium guide should get you started. All you need in terms of supplies you probably have lying around at home: aluminum foil, paper, cardboard, etc. I suspect Kelli Anderson’s This Book is a Camera ($27) might also work if you play with the exposure times?

Apply good sunscreen. You’ve got your eye protection down, now for the rest of yourself. The eclipse is happening in the middle of the day in much of the country, in what you hope will be complete sunshine, so bring some sunscreen. The Sweethome recommends this SPF 70 Coppertone for $9. Wear a cap. Stay in the shade. Bonus for shading yourself under trees: the gaps between the leaves will form little pinhole lenses and you’ll see really cool patterns:

Solar Eclipse Leaves

A nice pair of binoculars. If you’re in the path of totality, you might want a pair of binoculars to look more closely at the totally eclipsed Sun (after checking that it’s safe!!). I’m guessing you don’t want to buy a pair of specialty astronomy binoculars, so the best binoculars are probably ones you already own. If you don’t already have a pair, The Wirecutter recommends the Midas 8 x 42 binoculars by Athlon Optics ($290) with the Carson VP 8x42mm ($144) as a budget pick. (For solar filter options, see below.)

A solar filter for your camera. If you have a camera, they might make a solar filter for whatever lens you want to use. Hydrogen alpha filters will allow you to see the most detail — “crazy prominences and what-not” in the words of a photography pal of mine — but are also pretty expensive. You can buy solar filter sheets ($29) to make your own lens coverings for your camera, binoculars, or telescope. Quality will likely not be fantastic, but you’ll get something. Safety warning: place any filters in front of lenses or it can burn a hole in the filter (and then into your eye); i.e. don’t use binoculars in front of safety glasses!!

Note for budding solar photographers: Shooting the eclipse will be challenging. First there’s too much light and you’ll need a filter. Then when totality occurs, you’ll be in the dark needing a tripod and a fast lens. Plan accordingly…or leave it all at home and look at the thousands of photos taken by pro photographers after the fact.

Ok, that’s it. Have a good eclipse and stay safe!

Update: I removed a reference to the plastic-rimmed safety glasses I ordered because the image has changed on this item since I ordered them and published this guide…it’s now a wire-rimmed pair of glasses. I would recommend getting something else instead, just to be safe. (thx, @kahnnn)

Update: NASA has been alerted that some of the paper glasses being sold are not safe for viewing the eclipse. When buying, look for the ISO icon (referencing 12312-2) and for glasses made by these recommended manufacturers: American Paper Optics, Rainbow Symphony, Thousand Oaks Optical, or TSE 17. (via @ebellm)

Update: The Wirecutter has released their guide to The Best Solar Eclipse Glasses and Filters and they recommend the Celestron EclipSmart 2x Power Viewers (2-pack for $10), which provide not only certified eye protection but a nice 2X zoom.

Eclipse maps of the US, from 2000 BC to 100 years into the future

posted by Jason Kottke   Jul 11, 2017

Eclipse Map USA 2017

The Washington Post has a cool series of maps related to the total solar eclipse happening in August. The one above is a one-shot view of what the Sun will look like across the US on August 21 and there are other maps with captions like “The last eclipse over these areas occurred before Columbus’s arrival in 1492” and “Total solar eclipse paths over the continental U.S. since 2000 B.C.”

In the last 100 years, some areas have been in the paths of multiple eclipses: New England, for example, saw four. (During its World Series dry spell from 1918 to 2004, the greater Boston area alone saw two.)

Others weren’t so lucky. Just 200 miles away in New York, construction on the Empire State Building had not started yet the last time the city saw a total solar eclipse (1925). San Diego had a population of less than 100,000 the last time it was eclipsed (1923), and Chicago hasn’t seen a total eclipse at all in the last 100 years. An area near Tucson has the longest dry spell in the Lower 48: The last total solar eclipse it saw was in the year 797.

The U.S. mainland has averaged about seven total solar eclipses per century since 2000 B.C. Some areas have seen as many as 25 eclipses, while others, such as spots west of Minneapolis, have seen only four in the last four millennia.

NASA’s super accurate map of the 2017 eclipse

posted by Jason Kottke   Jun 14, 2017

Using data about the Moon’s terrain from the Lunar Reconnaissance Orbiter as well as elevation data on Earth, NASA’s Ernie Wright created a very accurate map of where and when the August 2017 eclipse will occur in the United States.

Standing at the edge of the moon’s shadow, or umbra, the difference between seeing a total eclipse and a partial eclipse comes down to elevation — mountains and valleys both on Earth and on the moon — which affect where the shadow lands. In this visualization, data from NASA’s Lunar Reconnaissance Orbiter account for the moon’s terrain that creates a jagged edge on its shadow. This data is then combined with elevation data on Earth as well as information on the sun angle to create the most accurate map of the eclipse path to date.

You can download maps of your area from NASA’s official eclipse website…I will be studying the Nebraska map closely.

Nebraska Eclipse Map

See also Eclipse Megamovie 2017, an eclipse simulator you can use to check what the eclipse will look like in the sky in your area, and what looks like an amazing eclipse watching festival put on by Atlas Obscura.

The 2017 total solar eclipse awarded to the United States

posted by Jason Kottke   Aug 21, 2014

2017 Solar Eclipse Map

I do not officially have a bucket list1 but if I did have one, watching a total solar eclipse would be on it. Was just talking about it the other day in fact. Well. I am pretty damn excited for the Great American Eclipse of 2017!

In August 21, 2017, millions of people across the United States will see nature’s most wondrous spectacle — a total eclipse of the Sun. It is a scene of unimaginable beauty; the Moon completely blocks the Sun, daytime becomes a deep twilight, and the Sun’s corona shimmers in the darkened sky. This is your guide to understand, prepare for, and view this rare celestial event.

It goes right through the middle of the country too…almost everyone in the lower 48 is within a day’s drive of seeing it. Cities in the path of the totality include Salem, OR, Jackson, WY, Lincoln, NE, St. Louis, MO (nearly), Nashville, TN, and Charleston, SC.

Weather will definitely play a factor in actually seeing the eclipse, so I will be keeping an eye on Eclipser (“Climatology and Maps for the Eclipse Chaser”) as the event draws near. Early analysis indicates Oregon as the best chance for clear skies. Matt, I am hereby laying claim to your guest room in three years time. So excited!!

  1. Also on this hypothetical bucket list: dunking a basketball, going to outer space, learning to surf, and two chicks at the same time.