Thank you Reddit!

We're signing off now, for more information about the eclipse: https://eclipse2017.nasa.gov/ For a playlist of eclipse videos: https://go.nasa.gov/2iixkov

Enjoy the eclipse and please view it safely!

Tomorrow, Aug. 21, all of North America will have a chance to see a partial or total solar eclipse if skies are clear. Along the path of totality (a narrow, 70-mile-wide path stretching from Oregon to South Carolina) the Moon will completely block the Sun, revealing the Sun’s faint outer atmosphere. Elsewhere, the Moon will block part of the Sun’s face, creating a partial solar eclipse.

Joining us are:

  • Steven Clark is the Director of the Heliophysics Division in the Science Mission Directorate at NASA.
  • Alexa Halford is space physics researcher at NASA Goddard Space Flight Center and Dartmouth College
  • Amy Winebarger is a solar physicist from NASA Marshall Space Flight Center
  • Elsayed Talaat is chief scientist, Heliophysics Division, at NASA Headquarters
  • James B. Garvin is the NASA's Goddard Space Flight Center Chief Scientist
  • Eric Christian is a Senior Research Scientist in the Heliospheric Laboratory at NASA Goddard Space Flight Center
  • Mona Kessel is a Deputy Program Scientist for 'Living With a Star', Program Scientist for Cluster and Geotail

  • Aries Keck is the NASA Goddard social media team lead & the NASA moderator of this IAMA.

Proof: @NASASun on Twitter

Comments: 3754 • Responses: 121  • Date: 

SwampDrainer3049 karma

Can't you dorks do something about the rain tomorrow?

NASASunEarth1265 karma

The NOAA weather forecasters are calling for clear skies across a good swath of the Western USA making for ideal eclipse watching in those places. We have 11 spaceborne satellites as well as the International Space Station (and balloons and aircraft) watching and measuring the big event tomorrow, so rain will not be a problem in many cases.

James B. Garvin (NASA)

NASASunEarth292 karma

Unfortunately no. But even if it's partly cloudy you still will have a good chance of seeing at least part of the partial eclipse and hopefully totality if you are in its path! Also if you are in the path of totality, you will still notice a change in temperature and potentially cloud cover. You can help us document all of these changes with the GLOBE app. https://observer.globe.gov/science-connections/eclipse2017 Make sure to take observations today as well so that we can compare what it's like today versus during the Eclipse! It's only with help from the public that we'll be able to collect all of this data! - Alexa Halford

LesserLizard2292 karma

Is it actually safe to look at the eclipse when it reaches totality? Like, could I wear my glasses when the shadow is starting to pass over, then take them off when it reaches totality?

NASASunEarth4495 karma

During totality, you don't need eclipse glasses and shouldn't wear them. It's actually easy to know when to take off the eclipse glasses, because you won't be able to see anything. When totality is over, as soon as any bright Sun peeks around the Moon, you need to put your glasses back on. - Eric Christian, NASA/GSFC

Sabmo2007 karma

Are there any specific experiments/investigations that the solar eclipse allows you to carry out that you couldn't do at other times?

NASASunEarth2388 karma

A coronagraph* is an instrument that observes the Sun's outer atmosphere, the corona. The instrument blocks out the direct light of the Sun, using a disk that is more than the diameter of the Sun. Using this instrument, scientists miss the lower part of the corona. But this region is visible during a solar eclipse, and so scientists take advantage of this opportunity to make measurements in this critical region. Mona Kessel (NASA)

  • Edited by moderator at 12:55, due to autocorrect changing 'coronagraph' to 'chronograph'

NASASunEarth371 karma

Absolutely because the eclipse allows us to see the deep solar atmosphere in a way that is not typical ! And we can even watch the eclipse from our Lunar Reconnaissance Orbiter (in orbit around the Moon) to watch the effects of the Moon's shadow across the US. In fact to study the solar corona directly we are launching the Parker Solar Probe mission next year to deliver a special scientific spacecraft just to explore this critical region of space.

James B. Garvin (NASA)

NASASunEarth295 karma

This eclipse is giving us a fantastic case study to test ionospheric models and models of radio wave propagation! When Nature is your laboratory, it's near impossible to control for all variables, so an event like the eclipse is a fantastic to validate and test that our models and understanding of things like the ionosphere are correct. You can find out more at this website https://eclipse2017.nasa.gov/science-ground - Alexa Halford

Tyrael1872 karma

[deleted]

NASASunEarth4351 karma

It depends upon how long you stare at the Sun. A split second won't do permanent damage (the first thing every kid does when you tell them not to stare at the Sun is to look at the Sun). But the longer you look, the more damage you'll do. Part of the problem is that there are no pain sensors in the retina, so you won't know how bad it is. And an eclipse is no worse than the Sun on any day, there is just more probability that someone will stare at the interesting phenomenon - Eric Christian, NASA/GSFC

NASASunEarth894 karma

Please do not look at the sun directly at any time -- our wonderful human vision system (our eyes) is not meant to "see" the intense infrared radiation from the Sun (which is our parent star). The approved solar safe viewing glasses will make the experience of this eclipse memorable and safe!

James B. Garvin (NASA)

Willabeasty145 karma

Except they're sold out everywhere...

NASASunEarth378 karma

Here's how to make an indirect viewer: https://youtu.be/vWMf5rYDgpc - NASA moderator

America_USA_1303 karma

How frustrating is it to hear people, in 2017, saying that the earth is flat?

NASASunEarth1826 karma

What you can do is to show evidence to the contrary. Pictures from the space station or the shuttle, high enough up to see the curve of the Earth. You can't see the curve from the ground, it does appear flat. if someone chooses not to believe the evidence, I don't know how else to get the message through. Mona Kessel (NASA)

NASASunEarth788 karma

I just ask them to draw a map. There is no way to get the distances between cities (and there are lots of plane flights every day) correct on a flat Earth. And they usually put Antarctica on the edge. I've been to Antarctica and have personal evidence that McMurdo Station (south of New Zealand) is not 20,000 miles from Palmer Station (south of Chile). - Eric Christian, NASA/GSFC

NASASunEarth377 karma

This wonderful eclipse is a great way of seeing how our Earth and Moon are far from flat! The irregular (polygonal) elliptical shape of the Moon's shadow as it passes from Oregon to South Carolina is one way of demonstrating that the Moon and Earth are not flat at all (except at very local scales such as in parking lots). So, these amazing space events (eclipses) are great ways of learning how our planets and parent stars (our Sun) operate. It is a beautiful dance!

James B. Garvin (NASA)

arkofcovenant1268 karma

Advice on what to do if it’s going to be cloudy? Will it be more impressive to be in the path of totality on a cloudy day, or outside of totality in a spot that’s more clear?

NASASunEarth1723 karma

You will still be able to see the sky grow dark if it is cloudy. You will miss the corona. However, you can stream in from NASA live on your phone or computer. Not as good as the real thing. https://www.nasa.gov/eclipselive Mona Kessel (NASA)

NASASunEarth354 karma

My personal opinion is that the darkness and temperature change during totality might be more interesting even under clouds than the partial eclipse. And if you're on the path of totality, you'll have hours of partial eclipse in case the Sun peeks through the clouds anyway. Or you can watch the excitement on one of the webcasts, nasa.gov/eclipselive or exploratorium.edu/eclipse (where I'll be) or NASA Edge. - Eric Christian, NASA/GSFC

NASASunEarth233 karma

That's a tough one. Granted since my specific field of research is more focused on how solar storms on the Sun affect our Magnetosphere, ionosphere, and atmosphere, I'm looking forward to seeing the sunspots that are currently active. So for me, the partial eclipse or the period before the and after totality may be just as interesting as totality itself. I know that many would disagree with me, but I find the sunspots to be incredibly cool! (granted I've also never seen totality so perhaps once I see that I'll change my mind :) ) - Alexa Halford

MFRoyer1266 karma

My home in Oregon is within the path of totality. This place is teeming with birds and other terrestrial wildlife during the days. I heard during the two minutes of total sun coverage that birds will stop chirping. What other happenings can I expect during that dark moment?

NASASunEarth2328 karma

Wow! You won the geographical lottery! Animals can behave strangely when it goes dark. Birds get confused, you might hear an owl hoot during totality or a rooster grow when the sun reappears. If you look at the horizon, you may see a 360 degree sunset since you are sitting in the center of a shadow. The temperature may drop 10 degrees. Good luck! Amy Winebarger

gardibolt1094 karma

Why is it always cloudy whenever there's an astronomical event?

NASASunEarth987 karma

I wonder this myself. I was at the 1999 eclipse north of Paris and it was completely clouded out. Amy Winebarger

givemethescotch648 karma

I read another post that stated the final total solar eclipse would occur roughly 600 million years from now. Can you explain why this is? Assuming the first occured sometime in the past, why would this phenomenon only occur for a (relatively long) period of time?

NASASunEarth881 karma

Since our natural satellite (the Moon) is slowly receding in its orbit around our own Earth in about 600-650 million years the Moon's orbit will not permit it to shadow a swath of Earth to produce what we call "totality"... but that is a long time so we have plenty more solar eclipses to enjoy here on Earth. Note that 650 million years is about the amount of time since advanced lifeforms first appeared in the fossil record hear on Earth! We have been tracking the very slow change in the Moon's orbit around the Earth for decades with improving capabilities using advanced laser ranging methods and that is why we can predict the time when the Moon will be too far away in its orbit to produce the type of eclipse we will experience here across the USA tomorrow. Hope this helps!

James B. Garvin (NASA)

vuntmaster641 karma

How can we tell if our eclipse glasses are inadequate? With so many fakes and recalls, I have no idea if the ones I have will be safe for my kids. Thanks.

NASASunEarth981 karma

Hopefully the ones you got are stamped that they are ISO approved. If you look through them, most things should look dark. For instance, if you look at a car, you should not see the sun's reflection on it. If you look at the sun, it should be a fairly dim ball with sharp edges, no halo. Good luck! Amy Winebarger

NASASunEarth368 karma

Safe eclipse glasses should have an iso 12312-2 certification on them and should clearly have the manufacturers name and address on them. You can then check the manufacturer's name with the American Astronomical Society's list of reputable vendors (https://eclipse.aas.org/resources/solar-filters). Also, even if they are from a reputable vendor, don't use them if they are damages (such as having any pinholes or scratches). - Eric Christian, NASA/GSFC

techcaleb447 karma

Destin from Smarter Every Day talked about shadow snakes that show up for a short time. What are these caused by, and do you have any tips for filming them tomorrow?

NASASunEarth509 karma

They are also often called shadow bands, and they only occur just before or just after totality. They also don't always occur. The best way to observe them is with a flat, white surface. An expanse of cement would work or spreading out a white sheet on the ground has been tried. We actually aren't completely sure what causes them. Some people think that they are caused by diffraction of light around the Moon. I think that it is more likely that they are due to atmospheric effects, and the bands are due to the fact that the Sun, near totality, is longer than it is wide. Similar to the patterns that form on the bottom of a pool. - Eric Christian, NASA/GSFC

good_names_all_taken371 karma

How does the path of totality change between eclipses? Is it pretty much random, or are some places on it more often than others?

NASASunEarth529 karma

The path of totality is not random. The positions of the Sun and Moon are known to better than 1 arc second accuracy. This means that on the Earth, the location of the track of totality is probably known to about (1.0/206265.0) x 2 x pi x 6400 km = 0.19 kilometers or a few hundred meters at the Earth's equator. So eclipse paths are predictable, and depend on orbital dynamics between the Sun, Earth, and Moon.
Mona Kessel (NASA)

BB-r8364 karma

Are there any particular measurements or data NASA is trying to collect from this solar eclipse? What if anything can you guys learn from an event like this? Thanks.

NASASunEarth301 karma

There are a great many new measurements that NASA and other agencies will be making to understand this eclipse. Just think about the network of satellites, aircraft, balloons, and ground observers now linked by the internet and social media that is now available in 2017! Even though the eclipse will zip by any single location at 2200 miles per hour (that's fast!), the cross-county network of observers plus our crew on the International Space Station and even our Lunar Reconnaissance Orbiter (in lunar orbit) will be participating. Unique measurements of the solar corona will be made with new sensors, some of which are even experimental, and this will help us get ready for next year's launch of the Parker Solar Probe which will directly explore the outer solar atmosphere for the first time. At NASA we investigate the radiation balance of our planet using satellites and increasingly capable physical models, so evaluating the short-term impact of air temperature fluctuations from the swath of totality across the US will be an input to our understanding, just as other short-term, dynamic events are in this fascinating process. For me, having our Lunar Reconnaissance Satellite look back at our Earth from its array of instruments at what can be observed about this solar eclipse is particularly exciting as we have not made such measurements before. We anticipate that the integrated suite of observations from this historic (for the USA) event will contribute to the body of scientific knowledge and even help us to understand solar transit events, which we will be using to investigate planets around nearby stars in the near future with our upcoming TESS and James Webb Space Telescope missions. Lastly, for those in the path of totality, it will be possible to see the planets Mercury and Venus during daytime hours, which reminds of these neighboring worlds and their scientific importance.

James B. Garvin (NASA)

NASASunEarth149 karma

There are several scientist, armature astronomers and citizens participating in the Citizen CATE experiment. We have a site here in Cookeville, TN (where I am viewing the eclipse). At 68 sites along the eclipse path, we will be taking identical data of the sun's corona during totality. At the end of the day, we hope we have a 90 minutes movie of the inner corona. It is actually really hard to see the inner corona any other way. We hope it will help us understand how mass and energy propagate away from the sun and into the solar system. There are lots of other science experiments happening, too. Amy Winebarger

NASASunEarth60 karma

Yup! There are a ton of measurements as people have mentioned below and you and others can help us get even more! If you're interested download the GLOBE observer app and help us document how the environment changes during an eclipse! https://observer.globe.gov/science-connections/eclipse2017 On both the GLOBE site and https://eclipse2017.nasa.gov/science you can find more information about all the wonderful science data that will be collected during the eclipse. This promises to be the best-observed eclipse in history! and we can make it even better with your help! - Alexa Halford

shrey-p97346 karma

No stores around me are in stock with solar eclipse glasses, and I don't want to use a pin hole projection any other safe recommendations?

NASASunEarth365 karma

(you use these techniques to view the eclipse indirectly - do not attempt to view the Sun itself through your hands or a pasta strainer. More here: https://eclipse2017.nasa.gov/safety) - NASA moderator

You can also use your hands, a pasta strainer, or just look at the shadows made from tree leaves! https://giphy.com/gifs/nasa-nasagif-solar-eclipse-xT39DdrVkGIFDAVEY0 - you can find out more at http://eclipse2017.nasa.gov/safety Alexa Halford

House_of_Borbon346 karma

How much different is a 99% eclipse and a total eclipse? I live in an area where there will be a 99.1% coverage of the sun, and we're not sure whether it's worth it to drive an hour away to get to a good area where there's 100% coverage.

NASASunEarth386 karma

I have never seen an eclipse personally, but I understand it is a pretty big difference! You might get something like the diamond ring effect (google for an image) and then it will go back to a partial eclipse. Try to get to totality! Amy Winebarger

NASASunEarth260 karma

Well, at 100% one is in the path of "totality" meaning that 100% of the sun will be blocked by the Moon and it will get dark! Anything less, while impressive and for many people rather evocative, will not produce the total darkness of totality. Much of the US will experience levels that extend from 60% to nearly 100%, so this entire event will be amazing across the US even if you are not in the narrow swath (about 70 miles wide) of totality. If you have the solar safe viewing glasses and are within an hour of the path of totality, you will experience a wonderful "show"! - Mona Kessel (NASA)

NASASunEarth133 karma

Like night and day... Or so I've been told :) It should be worth the drive, but make sure to start driving early as there are already reports of increased traffic along and towards the path of totality. Make sure to pack some extra snacks and water and perhaps some sunscreen as well. Also, maybe some car games for the kids :). Have fun and I hope you make it to totality! It should be worth it. If you miss it, you can see live coverage of the eclipse at https://eclipse2017.nasa.gov/eclipse-live-stream - Alexa Halford

PoisonousToxins273 karma

Is it safe to aim a DSLR camera at the eclipse? I heard it will ruin the camera but I don't understand how that would happen as I have aimed my camera at the sun many times before.

NASASunEarth394 karma

Not without the right filters while the Sun is not completely covered by the Moon. Any time you aim the camera at the Sun you run the risk of saturating and ultimately damaging the sensor, in the case of the DSLR, the CCD chip. If you are using an SLR or a DSLR while looking through the view finder and not the screen, you run a very high risk of seriously damaging your eyes as your focusing the Sun's light. You can find tips for safely taking photos of the eclipse here https://www.nasa.gov/feature/goddard/2017/five-tips-from-nasa-for-photographing-the-total-solar-eclipse-on-aug-21 - Alexa Halford

sasopocmarany271 karma

will there be an eclipse in other parts of the world in the near future?

NASASunEarth590 karma

There is a total eclipse somewhere on earth about every 18 months. The next one will be over the pacific ocean and parts of South America on July 2, 2019. Amy Winebarger

NASASunEarth224 karma

The next total solar eclipse will be July 2, 2019 and will be visible in Chile and Argentina. There is a total solar eclipse somewhere on Earth about every 18 months. - Eric Christian, NASA/GSFC

NASASunEarth173 karma

There is a non-NASA website that gives times and dates of upcoming eclipses worldwide: http://www.eclipsewise.com/

Due to bandwidth issues, NASA isn't hosting this site right now, there are plans to host this website in the future. - NASA moderator

archer-sc262 karma

Let's say there was no traffic and there was a road following the exact path of the eclipse. If I started at Oregon, how fast would I have to drive to keep up with the eclipse all the way to South Carolina?

NASASunEarth328 karma

The shadow of the moon is traveling at 1800 miles per hour, pretty fast! Amy Winebarger

NASASunEarth248 karma

The shadow of the eclipse moves very fast though at varying speeds depending where you are. Over Oregon, its moving over 2400 mph and over South Carolina, over 1500 mph. Elsayed Talaat

JammyOccuypse257 karma

Could you explain how solar eclipses are tied to proof of the theory of general relativity?

NASASunEarth452 karma

The eclipse of 1918 was used to prove Einstein's theory. A number of scientists took photographs, and the stars near the Sun were shifted in exactly the amount the theory predicted. It was a difficult experiment, the shift was small, but all of the observers basically saw the same effect. - Eric Christian, NASA/GSFC

ermergerdberbles257 karma

Will it be a total eclipse of my heart?

NASASunEarth228 karma

It will be of mine! Amy Winebarger

BigSchwartzzz179 karma

What will you all personally be doing as it's happening? Will you be monitoring it indoors? Watching it with your family and/or friends? Or cracking open a beer at some super cool NASA pool party?

NASASunEarth261 karma

I would love a NASA pool party! I will be in a stadium full of people, including my family. We are taking some science data during the eclipse, but hopefully it will be all set up and just running on its own during totality so we can enjoy those 2.5 minutes just like every one else. Amy Winebarger

NASASunEarth121 karma

I'll be watching with my kids and everyone else here in Charleston, SC. Elsayed

NASASunEarth109 karma

I'll be back at NASA Goddard in Maryland watching the partial eclipse and answering more questions! It's looking like it will be an exciting and long day. But then some of the most exciting work can begin when we can start looking at all the fantastic data coming in :) - Alexa Halford

oldbutgoldi151 karma

What is the biggest misconception people still have about solar eclipse?

NASASunEarth293 karma

I have mainly been talking to elementary school kids. The one thing I have tried to tell them is just how special the eclipse is and how rare it is to have one "in your backyard". Amy Winebarger

NASASunEarth51 karma

I've heard a number and many that I never even knew existed. But you can find a pretty interesting and complete list and the facts at https://eclipse2017.nasa.gov/eclipse-misconceptions - Alexa Halford

Empole144 karma

How did it feel when you realized you had the coolest job ever?

NASASunEarth217 karma

Pretty out of this world :) - Alexa Halford

NASASunEarth194 karma

I have the best job on earth and in space! I think about it every day! Amy Winebarger

WhiteIgloo133 karma

My son would LOVE to be an astronaut, are there any tips or recommendations that would make him stand out in the future (hes 6 almost 7)?

NASASunEarth221 karma

That is great! Becoming an astronaut is a really hard process, but he is getting an early start. There are two things that I can tell you about the astronauts I have met: they are passionate about space and science and they have really great personalities and can get along with lots of different types of people. Amy Winebarger (NASA MSFC)

tibtibs107 karma

Are any of you in Carbondale, Il? And if I bring liquor will you do a shot with me today?

NASASunEarth147 karma

We have a NASA Edge tent in Carbondale. Stop by and say hi to those scientists. Amy Winebarger

LastLTR106 karma

Are there any space-related foods (e.g., Tang, freeze-dried ice cream) that I should snack on while waiting for the eclipse? Love NASA!

NASASunEarth207 karma

Where I am, there is a run on moon pies and sun chips! Amy Winebarger

NASASunEarth104 karma

Make sure to stay well hydrated too so perhaps some sun tea? :) - Alexa Halford

among_shadows97 karma

I am at a location where the eclipse will be about 92% magnitude. Will the sky get any darker, or will I see anything special from where I am?

NASASunEarth110 karma

At 92%, I don't think the sky will get noticeably darker, but I have never seen an eclipse, so I am not sure. You will be able to see the partial eclipse from there and it will be worth watching! Use eclipse glasses or a pinhole viewer. Amy Winebarger

NASASunEarth89 karma

At 92%, you will probably notice the light getting dimmer and maybe a drop in temperature (take temperature measurements and use the NASA GLOBE app - https://observer.globe.gov/about/get-the-app - to help NASA understand the atmosphere better). With safe view methods, you'll see the Sun as just a narrow sliver, which is pretty neat. - Eric Christian, NASA/GSFC

jlw5286 karma

I live west of Portland. Is it worth the traffic to get better than 99.4%?

NASASunEarth109 karma

99.4% coverage is really good. I recommend you reach out to your local traffic authorities to get a better idea of the traffic forecast to make your decision. 99.4 % combined with the awesome coverage NASA will have for the entire celestial event may be the way to go. Either way...enjoy this spectacular event! -Steve Clarke

lannister8063 karma

If you're not in the path of totality, but say the Sun is going to be 88% covered, how dramatic is the effect going to be? Like, how dim will it be outside?

NASASunEarth74 karma

Unfortunately, I don't think it will dim outside at 88% (the sun is really bright!) But it will still be a cool thing to see! Amy Winebarger

Droct1255 karma

Can i use sunglasses or will i go blind?

NASASunEarth163 karma

Don't use sun glasses! You can do permanent damage to your retina. Eclipse glasses, #14 welders glass, or a pinhole viewer only. Amy Winebarger

ExaltB243 karma

How does the Eclipse go west to east? I've read that it does but so far I haven't heard any explanation the only video I seen on the issue didn't really explain anything. Also what's up with that strange looking demon face in space, it seems to be blacked out on Google at one time and it appears to be moving as a whole so it's not like it's some gas built up and expanding or anything. I don't have a link to the photo just yet but could edit it in when I get a chance, but I'm sure you already know what I'm talking about.

Thank You.

NASASunEarth70 karma

Because the Moon moves to the east in its orbit at about 3,400 km/hour. Earth rotates to the east at 1,670 km/hr at the equator, so the lunar shadow moves to the east at 3,400 – 1,670 = 1,730 km/hr near the equator. If you hold a ball and imagine it is the Earth with the continent of North America facing the Sun. The moon orbits Earth in the same direction as Earth spins on its axis. The Moon appears fist on the west side of the continent and then moves to the east. Try it with a ball. Mona Kessel (NASA)

NASASunEarth40 karma

It moves that way because of the relative motion of the Moon around the Earth and the rotation (spinning) of the Earth, both of which are fast -- so the shadow of the Moon during this solar eclipse moves from the Western US to the East because of this -- there is a wonderful description of this in an answer by Dr. Alex Young online and in recent articles that goes into greater detail.

James B. Garvin (NASA)

Kolyei39 karma

I went to dozens of rest stops along the way to the eclipse and they are all out of eclipse glasses. What is a good enough alternative to eclipse glasses? When I was a kid, I put several layers of negative film over my eyes on order to see the eclipse

NASASunEarth71 karma

14 welders glass or a pinhole viewer. I just went to Wal-mart last night and bought a colander with circular holes. If you hold that up, all the holes will show the partial eclipse. The place where you are going may have eclipse glasses. Good luck! Amy Winebarger

Umaiar45 karma

You're using the collander to project multiple images on a surface like many pinhole cameras in one... You're not intending to look at the sun through the collander, correct?

(I'm reading answers out loud to my daughter, and she feels the information is unclear.)

NASASunEarth45 karma

There are several scientist, armature astronomers and citizens participating in the Citizen CATE experiment. We have a site here in Cookeville, TN (where I am viewing the eclipse). At 68 sites along the eclipse path, we will be taking identical data of the sun's corona during totality. At the end of the day, we hope we have a 90 minutes movie of the inner corona. It is actually really hard to see the inner corona any other way. We hope it will help us understand how mass and energy propagate away from the sun and into the solar system. There are lots of other science experiments happening, too. Amy Winebarger

That is correct! Just look at the shadow of the colander on the ground. :) Amy Winebarger

FrozenApex36 karma

If you don't own glasses what can you do to see it?

NASASunEarth62 karma

There are a variety of ways to experience the eclipse without the solar-safe glasses -- these are described on the website eclipse2017.nasa.gov for anyone interested and in various online articles. Simply poking a pin-hole in a piece of paper and watching the effect of the Moon's blockage of the Sun on the ground is one approach, or looking at the ground under leafy trees to see the multitude of "mini-eclipses" from the filtering effects of the leaves. There are more elaborate devices that can be constructed using shoeboxes or larger ones as well. Hope this helps!

James B. Garvin (NASA)

InTupacWeTrust28 karma

Do you think you'll go to Mars in the next 4 years?

NASASunEarth65 karma

I personally will not be going to Mars in the next 4 years (or ever!)
Amy Winebarger

NASASunEarth36 karma

In the next 4 years? No, but in my lifetime? Maybe, hopefully! It would/will be an amazing accomplishment! - Alexa Halford

AtomicFreeze25 karma

Forecast isn't looking good here. :( Will the partial eclipse (near 90% coverage) still be noticeable through clouds?

NASASunEarth31 karma

I am not sure, I don't think so. I was at a total eclipse that was completely clouded out. It was just slightly darker during the eclipse. Amy Winebarger

drag0nslave14 karma

Reposting from another thread:
Back in my younger days, we used the magnetic film of a floppy disk to look at the eclipse. Was that good enough protection?

NASASunEarth12 karma

I have never heard of that. I personally would not suggest that, instead use approved solar eclipse glasses or #14 welders glass or make a pinhole viewer. Amy Winebarger

NASASunEarth10 karma

We don't recommend that. - Eric Christian, NASA/GSFC

Memepocalypse4203 karma

What time is Los Angeles going to be able to see the Eclipse?

NASASunEarth3 karma

It should start at 9:05 and end at 11:44. You will see a partial eclipse the whole time, so use glasses or a pinhole viewer to watch. Amy Winebarger

NebulousComa3 karma

Is it ok to wear a welding helmet to view the eclipse?

NASASunEarth5 karma

From the NASA webpage on safely watching the eclipse (https://eclipse2017.nasa.gov/safety) - "Experts suggests that one widely available filter for safe solar viewing is welders glass of sufficiently high number. The only ones that are safe for direct viewing of the Sun with your eyes are those of Shade 12 or higher." Elsayed Talaat

DanielTako3 karma

I'm not in direct totality of the eclipse, but very close. When it reaches the "totality" for me, can I take off my special glasses I have or since the sun will still shine through at me somewhat, I can't take them off?

NASASunEarth9 karma

If you are not in the path of full totality, you should not look at the sun directly without eclipse glasses at any time. Elsayed Talaat

Redbaron553 karma

If I use a shade 10 welding shield tomorrow will that be enough protection?

NASASunEarth4 karma

From the NASA webpage on safely watching the eclipse (https://eclipse2017.nasa.gov/safety) - "Experts suggests that one widely available filter for safe solar viewing is welders glass of sufficiently high number. The only ones that are safe for direct viewing of the Sun with your eyes are those of Shade 12 or higher."

Elsayed Talaat

_bieber_hole_692 karma

Will you folks be making the journey to see the full totality tomorrow?

NASASunEarth12 karma

I drove from Maryland to South Carolina with my kids last night in order to catch the totality. Very excited to see it tomorrow. Many NASA personnel are going to be all along the path of totality. Elsayed

NASASunEarth12 karma

I'm already in Casper, Wyoming (and have been since Friday). I'm working with the Exploratorium science museum (San Francisco) on a live webcast tomorrow (www.exploratorium.edu/eclipse) and we'll also be supplying telescope feeds to the NASA TV show (nasa.gov/eclipselive). - Eric Christian, NASA/GSFC

NASASunEarth7 karma

There are several of us spread out across the country from Oregon to South Carolina to cover the path of totality as it traverses the continental U.S. - Steve Clarke

NASASunEarth6 karma

I am in Cookeville, TN. I have been here all week talking to school kids about the eclipse. Amy Winebarger

anti-pSTAT32 karma

What research is being conducted by NASA scientists during the eclipse that can only be conducted during that time? How does the eclipse enable the research, what questions are being addressed, and what are expected outcomes?

NASASunEarth3 karma

During a total eclipse scientists get a rare opportunity to view to view part of the solar atmosphere that we normally can't see from the ground or even space, the lower part of the corona, the outer part of the sun's atmosphere. Because this time, the path of totality goes over so much land area, we have an opportunity to measure the solar corona over about 90 minutes, a great opportunity to look at temporal variability of this part of the solar atmosphere. Elsayed Talaat Elsayed Talaat

NASASunEarth2 karma

There is similar question above that has been answered both by me and James B. Garvin (NASA). It was asked by BB-r8. Amy Winebarger

skinsballr2 karma

Since many articles say to not point your smartphone directly at the sun to take photos/video during the eclipse (blurry image; the ruining of the camera lens), what is the best method to videotape the 1-3 minute span of the total eclipse? To place the eclipse sunglasses in front of the camera lens when recording?

NASASunEarth14 karma

Using eclipse glasses in front of your camera during a partial eclipse can still damage your camera, because cameras focus light and the eclipse glasses are not made for that. If you don't have a solar filter, I would not recommend taking pictures of the partial eclipse. During totality, there isn't that problem, the corona is much dimmer than the Sun, and you don't need to wear the eclipse glasses or put them in front of your camera. Still, we recommend that you spend your time actually looking at the total eclipse, because your eye will see more detail than your camera, and you won't be able to take images as good as the professionals. - Eric Christian, NASA/GSFC

Empole2 karma

Do computer scientists have a place at NASA?

NASASunEarth4 karma

Of course! We have lots of computer scientists at NASA. Amy Winebarger

TrapperJon2 karma

Ok, so not technically eclipse, but sun related. How big of a solar flare would it take to wipe out the worldxs electrical grids and how common are flares of that size? If it were to happen, how much warning would we have before it hit Earth?

NASASunEarth5 karma

It's hard to answer that type of question because a lot of factors would have to be "just right" for a storm to have a huge impact on the earth. Flares that large don't happen frequently.

In terms of travel time for a flare or coronal mass ejection to reach the earth: It takes about 8 minutes for the light to get to the earth from the sun, about 30 minutes for very energetic particles to get from the sun to the earth and about a day for the bulk of plasma and magnetic field to get from the sun to the earth.

Amy Winebarger

GringoKY2 karma

Is there any chance of seeing solar flares or the like during the eclipse? Is this an active solar time?

NASASunEarth3 karma

There is an active region on the limb of the sun! It could cause some interesting solar phenomenon. It would be unlikely to see a flare, but it will look very cool, regardless. Amy Winebarger

Theedon2 karma

How do we know people will go blind if they look at it? When was the lab study done?

NASASunEarth2 karma

Do you know how if you use a magnifying glass, you can start a fire? The lens of your eye will focus the suns light on your retina and cause irreparable damage. Amy Winebarger

Thatoldays2 karma

This is little bit off track but I would be glad if you answered. What do you think about movie Interstellar?

NASASunEarth2 karma

I never saw that movie. Sorry! Amy Winebarger

Empole1 karma

I don't know if I'll get a chance to find certified eyewear for the eclipse. Is there any household items I could use to properly enjoy it?

NASASunEarth1 karma

A colander that has circular holes! Look at the shadow it makes during the partial phase. Amy Winebarger

carlossolrac1 karma

Hey NASA, big fan of space exploration! My question is; what sight is more beautiful to watch. Solar eclipse or lunar eclipse?

NASASunEarth2 karma

It is a matter of taste, but my vote would be for solar eclipse! Amy Winebarger

tannerhallman1 karma

Is this the rarest astronomical event visible from Earth with the naked eye?

NASASunEarth6 karma

Total Solar eclipses are not rare -they occur somewhere on Earth every 18 months. The path of totality changes every time, so it is rare for any one region on Earth to see another eclipse soon after the previous one. Seeing Halley's comet come around back in 1986 and then 30 years later was rarer than the total solar eclipse phenomena.
Mona Kessel (NASA)

ItsMrZombie1 karma

Could I overlay 5 layers of 2.5% (.5% light) car tint to view the eclipse? Or would that still be too much light / incorrect filtering?

NASASunEarth3 karma

I don't think you can use that. We can only recommend certified eclipse glasses or #14 welders glass. Amy Winebarger

splashgordon8241 karma

If I take video or pictures of the eclipse can it hurt the lens of my camera?

NASASunEarth2 karma

I don't think it will hurt the lens, but it might hurt the detector. You could use a filter. If it is the camera on your phone, you could put the eclipse glasses over the lens. Amy Winebarger

Talexe1 karma

Eclipse aside - what's your favourite fact about the sun that we might not have heard before?

NASASunEarth5 karma

I think it's fun that the Sun is a variable star. Everything that the Sun emits; light, heat, solar wind, energetic particles, magnetic field, x-rays, gamma rays, etc. varies with time. - Eric Christian, NASA/GSFC

nhadams21121 karma

Would something like a 250 shade ark welding mask work?

NASASunEarth2 karma

I don't know about 250 shade ark, but #14 welders glass will do. Good luck! Amy Winebarger

GalenMarrek661 karma

What makes solar eclipse glasses special?

NASASunEarth1 karma

They are a very good filter of visible light and reduce the sun's light to a level that won't hurt your eye. If you put them on, you won't be able to see much else (you couldn't drive in them, for instance, they are much "darker" than sun glasses). Amy Winebarger

Howtogetawaywithlife1 karma

Is it true that solar eclipse may cause earthquake/tornado, or is it just a misconception?

NASASunEarth2 karma

This is a misconception. Solar eclipses are just a brief astronomical phenomenon. They have no lasting impact on the earth, except perhaps in the minds of people who view them. Amy Winebarger

Ineedfamilyadvices1 karma

What's the difference between just regular old sunglasses to solar eclipse glasses?

NASASunEarth1 karma

Solar eclipse glasses block out much more light. You could not drive in them, it would be too dark. In fact, you can't see much except for the sun with solar eclipse glasses on. Amy Winebarger

Cafe_link1 karma

I heard that Xray film could be used instead of glasses. Is there any truth to this? Yes or no is sufficient.

NASASunEarth2 karma

No. Amy Winebarger

The_True_Dr_Pepper1 karma

How long can I look at the partial eclipse unaided before it affects my vision permanently?

NASASunEarth4 karma

Please NEVER look at the partial eclipse directly without eclipse glasses. Elsayed

NASASunEarth2 karma

There are other indirect methods for viewing the partial eclipse. You can even make your own pinhole camera imager with just a piece of paper and a pencil. Please go to eclipse2017.nasa.gov for ideas and instructions! Elsayed

NASASunEarth2 karma

Repeating an answer from before - A split second won't do permanent damage (the first thing every kid does when you tell them not to stare at the Sun is to look at the Sun). But the longer you look, the more damage you'll do. Part of the problem is that there are no pain sensors in the retina, so you won't know how bad it is. And an eclipse is no worse than the Sun on any day, there is just more probability that someone will stare at the interesting phenomenon - Eric Christian, NASA/GSFC

86972939301 karma

What's your favourite book about space?

NASASunEarth6 karma

There are so many! I suppose all of us who explore space have our own favorites both in non-fiction but also in fiction. My personal favorites include the fictional book "DUNE" (Frank Herbert) just for fun, and the non-fictional writings of Steven Hawking and Steven Jay Gould and Carl Sagan. One personal favorite is "The Martian Landscape" which was published by NASA and written in part by T. A. Mutch back in the late 1970s. But there are a great many meaningful and compelling books about space so find your own favorite!

James B. Garvin (NASA)

NASASunEarth4 karma

That's a hard question for me. I have read a lot of academic books about space that I love. My very first space physics text book in graduate school was "The physics of space plasma" by Parks, I still open that now. For fiction, I loved reading Isaac Asimov. Amy Winebarger

terevil1 karma

Do you all have anyone out at Debow Park in Hopkinsville?

NASASunEarth2 karma

There are several solar physicists and NASA scientist in Hopkinsville, I don't know if they will be in Debow Park, though. Amy Winebarger

ShadesofCold0 karma

If I face my back to the eclipse and use the selfie cam on my phone is that a safe way to view, in the absence of glasses?

NASASunEarth1 karma

From FAQ at eclipse2017.nasa.gov: There is no valid reason why you would want to point your smartphone camera at the brilliant, un-eclipsed sun without putting a filter over the lens. During totality, you do not need the filter, of course! Unless you have a telephoto lens for your smartphone, you will only be able to take unmagnified images of the eclipse in your sky. These photos can be very exciting because the field-of-view is large enough that you can compose the shot with your friends and local scenery in the shot, at the same time a recognizable, eclipsed sun during totality hangs dramatically in the darkened sky. You will easily be able to capture with most smartphone cameras the darkened disk of the moon surrounded by a clearly recognizable bright solar corona. Many examples of these kinds of wide-angle shots can be found on the Internet. Of course, if you use the camera’s digital zoom, you will see a pixelized, enlarged image that will not show much actual detail in the corona. To get around this, you need a telephoto lens for your smartphone. Mona Kessel (NASA)

celtics560 karma

Can i photograph the eclipse through welders glass? If so what is the minimun i need.

NASASunEarth1 karma

From the NASA webpage on safely watching the eclipse (https://eclipse2017.nasa.gov/safety) - "Experts suggests that one widely available filter for safe solar viewing is welders glass of sufficiently high number. The only ones that are safe for direct viewing of the Sun with your eyes are those of Shade 12 or higher."

Also, here is a webpage on how to safely use telescopes and binoculars to view the eclipse: https://eclipse.aas.org/eye-safety/optics-filters

Elsayed Talaat

NASASunEarth1 karma

We suggest #14 welders glass. And yes, you can photograph through it, it should look very cool! Amy Winebarger

shaneman150 karma

What should we do if we don't have the special glasses??

NASASunEarth1 karma

A pinhole viewer. I personally like using a colander with circular holes. Good luck! Amy Winebarger

Buttons8400 karma

I looked at the sun with solar glasses and almost thought I could see sunspots. Is this possible or was it my imagination?

NASASunEarth2 karma

No, you might have seen them! There are beautiful sun spots in the very center of the sun right now, i will be looking for them tomorrow. Amy Winebarger

Iehouah0 karma

What will be the path of the next solar eclipse on the us mainland?

NASASunEarth1 karma

The next eclipse in 2024 will start in the US in Texas and cut north-east. Amy Winebarger

NASASunEarth1 karma

The next eclipse over the contiguous US in 2024 will go from Texas to Maine. Elsayed Talaat

BenMears51500 karma

What does NASA know about Aliens visiting us from space?

NASASunEarth5 karma

Nothing, and it's not a secret that NASA could (or would) keep. We are a civilian agency with lots of creative, independent-minded people, and we don't sign non-disclosure forms. - Eric Christian, NASA/GSFC

Smartt880 karma

Any good tips for trying to photograph the eclipse?

NASASunEarth5 karma

One interesting idea is to photograph the ground under leafy trees to see the many small shadows of the eclipsed sun (miniature eclipses) -- there are some artistic ways to do this and capture beautiful (but indirect) views of this amazing event.

James B. Garvin (NASA)

NASASunEarth2 karma

See above reply! Mona Kessel (NASA)

Nakatomi20100 karma

I understand that I should not look directly at the Eclipse, however, can I use my phone between the Eclipse as I as a cover and stare at the phone? I recognize that I'll run the risk of damaging the electronics in the phone in the process, however, as the phone is getting replaced in a week I don't care if the camera get wrecked. If anything, I'm curious as to how wrecked it'll be.

Will I still foul up my vision if I use the phone's screen to watch it?

NASASunEarth1 karma

If you use your phone, you probably can't see the partial phase of the eclipse. One thing you can do is cover the lens of your phone with the eclipse glasses. Good luck! Amy Winebarger

the_time_weaver0 karma

I'm poor, is there any other way to "look" at an eclipse other than that pinhole cardboard thing? Any magical secrets are appreciated.

NASASunEarth2 karma

No magical secrets! Eclipse glasses, a pinhole viewer or #14 welders glass. I personally like using a colander as a pinhole viewer, google for cool eclipse images. Amy Winebarger

sonic_tower0 karma

Any tips for photography for a dude with a phone in totality?

NASASunEarth2 karma

From FAQ at eclipse2017.nasa.gov: There is no valid reason why you would want to point your smartphone camera at the brilliant, un-eclipsed sun without putting a filter over the lens. During totality, you do not need the filter, of course! Unless you have a telephoto lens for your smartphone, you will only be able to take unmagnified images of the eclipse in your sky. These photos can be very exciting because the field-of-view is large enough that you can compose the shot with your friends and local scenery in the shot, at the same time a recognizable, eclipsed sun during totality hangs dramatically in the darkened sky. You will easily be able to capture with most smartphone cameras the darkened disk of the moon surrounded by a clearly recognizable bright solar corona. Many examples of these kinds of wide-angle shots can be found on the Internet. Of course, if you use the camera’s digital zoom, you will see a pixelized, enlarged image that will not show much actual detail in the corona. To get around this, you need a telephoto lens for your smartphone. There are many styles of telephoto lenses for smartphones. Avoid the ‘clip on’ lenses because they constantly slip and have to be precisely lined up on the camera lens to work. They are often of low optical quality. The best lenses are rated as 12x and above, and come with their own smartphone mounting bracket. At these magnifications, a tripod is essential because of camera jitter. A decent 12x lens and tripod adapter will cost you about $30.00, but you can also use this system for great ‘close up’ shots in sport and nature settings too! The telephoto lens will give you enough magnification that you will clearly see some of the details in the bright corona. You should test your system by taking night-time photos of the moon so you understand how large and detailed the moon will appear in your shot. The sun/mon during eclipse are equal-sized so this is a good way to compose your eclipse shots too. Also experiment with the settings on your camera using a downloadable app like Camera+ or NightCap Pro, which allow you more flexibility in setting up the exposure, f/stop and other factors. For more information on eclipse photography with smartphones, read the project details found at our Citizen Explorers page. Above all, don’t forget to put your smartphone down and enjoy the eclipse with your own eyes! Mona Kessel (NASA)

sticazz0 karma

Can you make a gif showing how the shaded area moves in time?

NASASunEarth7 karma

We have very good animations of how the Moon's shadow will move during tomorrow's eclipse (see for example https://svs.gsfc.nasa.gov/4321), but we also have spacecraft that can take movies of the shadow from space, such as the NOAA/NASA DSCOVR spacecraft. Here is a DSCOVR movie from last year's eclipse (https://epic.gsfc.nasa.gov/galleries/2016/solar_eclipse/video). We expect to have an equivalent movie of tomorrow's eclipse. - Eric Christian, NASA/GSFC

NASASunEarth6 karma

there are wonderful 3D style animations of the Moon's shadow across the US at eclipse2017.nasa.gov and other websites!

James B. Garvin (NASA)

McLeech-2 karma

Is it possible for a man to land on the moon?

NASASunEarth1 karma

Absolutely, and here at NASA we were able to land six different teams of humans on the Moon between 1969 and 1972 as part of our Project Apollo, including such astronauts as Buzz Aldrin, Dave Scott, and Jack Schmitt. Today we have a capable robotic Lunar Reconnaissance Orbiter in low orbit around the Moon mapping its surface in ways that were not possible (or even invented) in the late 1960's, and producing images and topographic information of the same quality as that we have for key places here on Earth. Getting humans back to the Moon to learn to live off planet and to investigate the compelling records of the history of our Earth-Moon-Sun system has been a long-term goal of space exploration and today we are preparing the way for leaders in our country to decide if that is the path we should take. In direct answer to your question, it is possible to safely land women and men on the Moon because we have done so multiple times. Returning to the Moon's surface with advanced robotic systems including rovers and "hopping" vehicles is also possible with today's technologies and it may be possible for human explorers in deep space to tele-operate vehicles on the lunar surface without being there themselves.

James B. Garvin (NASA)

dredawg1-3 karma

What affect will this have on climate change? LOL

NASASunEarth2 karma

Anyone interested can download the GLOBE app and become a part of measuring the impact of the solar eclipse tomorrow. Solar eclipses have been a part of Earth history for millions of years and during those times the record of our planet's environmental history has been remarkable and topsy-turvy. Single (albeit exciting events) such as tomorrow's eclipse are part of a system of events that scientists measure to gauge how the Earth's atmosphere (and climate system) respond to a broad variety of events (including eclipses, volcanic eruptions, asteroidal impacts etc.). For people interested in this topic, getting involved with the free GLOBE app and participating in measurements of the impact of the eclipse can be meaningful and fun!

James B. Garvin (NASA)