Ask an Expert

Ask an Expert: An 'Eclipse' is More Than a Movie
Total lunar eclipse in January 2000. Total lunar eclipse captured January 20-21, 2000. (Mr. Eclipse/Fred Espenak)
Loops of material around the sun during an eclipse Loops of material seen at the edge of the sun during the total phase of an eclipse. (NASA/MSFC/Mitzi Adams)
Partial solar eclipse, captured by Hinode spacecraft in July 2009. Partial phase of a total solar eclipse, captured by the Hinode spacecraft on July 22, 2009. (NASA/JAXA)
A shadow from the moon falls on Earth, seen from the International Space Station in 2006. A shadow of the moon falls on Earth, seen from the International Space Station. (NASA)

More Information
Link: NASA, Solar Eclipse July 11, 2010
FAQ: All About Eclipses (pdf)
Link: NASA: Lunar & Solar Eclipses
Image Gallery: Eclipses
Video Gallery: Eclipses
Link: NASA's "Summer Science Camp"
On June 30, the vampire/werewolf thriller Eclipse will darken theaters around the world. On June 26 and July 11, Nature's eclipses will temporarily darken the skies over parts of the globe -- and you won't even have to buy a ticket to see the show.

The first lunar eclipse of 2010 occurs on June 26 and will be visible from much of the Americas, the Pacific and eastern Asia. A lunar eclipse only happens at full moon, and only if the moon passes through a portion of Earth's shadow. On July 11, the second solar eclipse of 2010 occurs, achieving total eclipse within a narrow corridor across Earth's southern hemisphere. A solar eclipse only happens at new moon when the moon passes between Earth and the sun.

On Thursday, June 24, solar astronomer Mitzi Adams from NASA's Marshall Space Flight Center will answer your questions about lunar and solar eclipses: what causes them, how often they occur and the best places to see one of nature's most dramatic celestial shows.

Joining the chat is easy. Simply visit this page on Thursday, June 24 from 3-4 p.m. EDT. The chat window will open at the bottom of this page starting at 2:30 p.m. EDT. You can log in and be ready to ask questions at 3:00.

See you in chat!

More About Chat Expert Mitzi Adams

In her 22-year career at the Marshall Space Flight Center, Mitzi Adams has conducted research for a variety of solar missions, including work with Marshall's vector magnetograph, a pioneering instrument that studied magnetic fields in sunspots; SOHO, a mission to study the sun from its deep core to the outer corona; and Hinode, a project to improve our understanding of the sun's magnetic field and the mechanisms that drive solar eruptions.

As a guest lecturer for science courses at the University of Alabama in Huntsville, Adams works to sustain enthusiasm and engagement at the college level. She has led several sessions of "Theories of the Universe," a class that explores how various cultures perceive the cosmos, discussing the astronomy-savvy Maya and Inca civilizations of Central and South America, respectively. She’s well-versed in the subject matter -- and not just the astronomy. An accomplished hiker and an avid student of ancient cultures, Adams has repeatedly vacationed in Peru and Guatemala to visit the ruins of these lost empires.

"That’s what's great about astronomy as a career," she said. "It's a fascinating blend of sciences -- physics, chemistry, geology, history, mathematics -- that keeps it new and exciting and makes it relevant to our everyday lives."

Since 1970, Adams has taken part in four total-solar-eclipse studies in Georgia (March 1970), Chile (November 1994), Romania (August 1999) and Africa (June 2001). She is looking forward to driving north toward Nashville for another one closer to home in August 2017.

Chat Transcript

(Moderator Jason): Today's Chat is Scheduled to Begin at 3pm ET. Please begin to ask your questions by typing them into the box at the bottom of the screen and clicking the 'Ask' button on the right. We'll begin answering them in about ten minutes. Thanks for your patience.

(Moderator Jason): Hello everyone. Our chat will begin momentarily. Please begin to ask your questions by typing them into the box at the bottom of the screen and clicking the 'Ask' button on the right. We'll begin answering them in just under a minute. Thanks for your patience.

Ediz_Celik: Do solar eclipse affect earthquakes ?

Mitzi: There's no correlation between solar or lunar eclipses and increased earthquakes or increased storms.

Akarsh_Valsan: When do solar eclipses occur?

Mitzi: Solar eclipses happen when the moon comes between the Earth and the sun. There's another condition, though -- all three have to be in the same plane. What I mean by the same plane...if you think of three balls sitting on a tabletop, all three would be on the same plane. This is similar to the sun/Earth/moon, and sometimes the moon will be above the tabletop plane -- other times it will be below. See the FAQ link above on this page (right side under photos).

Abishek: When did NASA start the study of eclipse?

Mitzi: It's been a part of astronomy since its inception.

Akarsh_Valsan: What is the study of eclipses known as?

Mitzi: "The study of eclipses." :) It's all part of studying astronomy.

Ediz_Celik: What is the best way to look eclipses with telescope?

Mitzi: Looking at a solar eclipse through a telescope can be dangerous -- you have to have a proper filter. The safest way is through a method called projection, where you actually take the eyepiece out and project the image onto a sheet of paper behind the telescope, without looking at the sun. You move the sheet of paper back and forth until you get a focused image. During a total solar eclipse, it's safe to look at the sun during totality, but ONLY during totality! Looking at a lunar eclipse with a telescope is safe, but you don't really need a telescope -- your eyes are better instruments in this case.

Ediz_Celik: If you study the Sun's corona, is a solar eclipse the best chance to see it?

Mitzi: There are many space-based telescopes that are very well-equipped to study the sun's corona -- however, during a total solar eclipse, one can study the inner corona in white/visible light, which is not possible otherwise.

Akarsh_Valsan: What date was the most dangerous solar eclipse ever?

Mitzi: There's no danger in a solar eclipse, unless you look at the partial phases with your unprotected eyes. Sunglasses are NOT protection -- special filters are required.

Djbelter: Is there any benefit to study eclipses anymore? Any new science to learn?

Mitzi: The benefit is to study the inner corona in visible/white light and to link it with the outer corona, which we can see with space-based telescopes.

zzz_last_alphabetically: How often do solar eclipses happen?

Mitzi: You can have as many as five solar eclipses in a single year, but that's not very common.

Abishek: Can we see eclipses through reflections in a mirror? Will it damage our eyes?

Mitzi: Yes, you can see the reflection in a mirror. It's probably not good to look at the reflection directly because it will be very bright. You can actually reflect that image onto a piece of paper, and that would be safe to view.

Anant007: Why do these eclipses occur?

Mitzi: Eclipses happen when the moon moves between the Earth and the sun -- that's a solar eclipse. When Earth is between the moon and sun, that's a lunar eclipse. All three have to be in the same plane. What I mean by the same plane...if you think of three balls sitting on a tabletop, all three would be on the same plane. This is similar to the sun/Earth/moon, and sometimes the moon will be above the tabletop plane -- other times it will be below. See the FAQ link above on this page (right side under photos).

summer:00: Where in the USA will the next lunar eclipse be seen?

Mitzi: On Dec. 21, all over the U.S.

Bartsch: What makes the moon go around the Earth?

Mitzi: The moon's orbit around the Earth is controlled by gravity.

celestialnebulae13: Where would be a great place to watch a lunar eclipse?

Mitzi: Probably the best place is where the sky will be dark and away from city lights -- but a lunar eclipse should be easily visible anywhere you can see the sky.

yyy_2nd_in_order: Where is the best place to view the next lunar eclipse, and with what?

Mitzi: The next lunar eclipse in December will be visible throughout the Americas. One could walk into the back yard -- or the front yard! -- to see it, assuming there are no clouds. No telescope is required. Lunar eclipses are best viewed with the unaided eye. However, while the eclipse is going on, you could use a telescope to look at the craters and mountains on the moon.

(Moderator Jason): We're working to get through all of the great questions you've asked us. Keep them coming! To submit your own question, please type it in the box at the bottom of the window and click the 'Ask' button on the right side of the box. Thanks for your patience as we answer your questions.

StudentAtJPL: I once did a project in high school and wanted to see any relationships between sun spots and earthquakes. Have you found any relationship with these ejections from these spots with anything at all?

Mitzi: No, no correlations between sunspots and earthquakes. However, associated with sunspots are solar flares and coronal mass ejections (CMEs). Charged particles -- electrons, protons -- can be emitted from these explosions. These interact with Earth's magnetic field and can affect GPS, satellites, and even the health of astronauts.

summer00: Do eclipses affect birds or bugs during their time?

Mitzi: Yes, they do. Interestingly, during the totality phase of an eclipse – when the sun is totally covered -- birds will go to roost and try to go to sleep, and night insects like crickets will begin to sing. Basically, they become confused when it becomes night in the middle of the day!

AkarshValsan: Are eclipse glasses safe for looking at the sun during a solar eclipse?

Mitzi: Eclipse glasses can be safe to view the sun during solar eclipses, but they're fragile and should be checked for tiny holes before using them. You can check them easily. Hold the glasses out so that sunlight passes through the glasses, then hold your opposite hand underneath and make sure no light is falling on your hand.

PJ: What types of easy experiments can the lay person do to actually help study the sun during an eclipse?

Mitzi: I can think of two things you can do. First, you could study the temperature changes that occur during a solar eclipse. This could be done at various heights above the ground to form a temperature range. Secondly,you could one could study the shape of the corona through high-rez photographs and make correlations between the current eclipse and previous eclipses. In other words, how does the corona change?

abishek: In hindu religion our fore fathers say that an eclipse occur when a snake swallows up the sun.

Mitzi: Eclipses in Hindu are related to Rahu and Ketu, which are actually associated with the nodes of the moon's orbit. There are two times when the moon can be in the same plane as a line between the Earth and the sun. This is called the ecliptic -- when the nodes occur is when elipses are possible. Tradition says that Rahu is the head of a demon, and Ketu is the tail. I suspect that the ancient Hindu actually knew about the nodes.

AkarshValsan: When will the next solar eclipse occur?

Mitzi: July 11 is the next opportunity.

JohnDoe: What is totality?

Mitzi(: Totality is when the sun is totally eclipsed by the moon. At that time, the solar corona can be seen and sometimes prominences (see the photo at the top of this page).

Larry: Mitzi, wil you be doing anything special for this weekend's eclipse or next month's solar eclipse?

Mitzi: Actually, this weekend's eclipse will be barely visible here, but I plan to look for it. Unfortunately, I don't have the resources or time to view the July eclipse.

abishek: Ma'am, what are special filters known as?

Mitzi: Filters which are safe for viewing an eclipse can include #14 welder's glass. Other filters are sold commercially under the name "eclipse glasses." There are also filters for telecopes that attach at the front of the telescope, and should be purchased through the telescope manufacturer or distributor. NEVER use a filter which screws into an eyepiece! Heat from the telescope is focused on these pieces, so they can and do crack -- I know from experience.

celestialnebulae13: What causes the moon to have a red glow during a lunar eclipse?

Mitzi: This is from light passing through the Earth's atmosphere, and the red color is not absorbed as readily. If there is a volcanic eruption which puts a lot of aerosols into the upper atmosphere, the color can be very deep, ruddy red.

Ediz_Celik: Which observatories are "into" studying eclipses?

Mitzi: Every observatory will look at an eclipse, if they can. But most observatories are stationary, and eclipses are visible only on very small parts of the Earth.

JJ_Jordan10: Do you know if animal behavior alters when a eclipse is near?

Mitzi: Animals will "roost" or try to sleep, and night insects will become active, such as crickets singing.

AkarshValsan: Ma'am, you said that the rays are bright and unsafe. So do these rays contain both UV light and infrared light?

Mitzi: Yes, that' correct, Akarsh.

Anant007: Okay then what does happen to sun or moon during the eclipse -- meaning any changes?

Mitzi: There are no changes to the structures or behaviors of the moon or sun during an eclipse.

summer00: What is the thin red layer around the sun often seen from a solar eclipse?

Mitzi: That's the chromosphere. My photo on this page shows prominences that are very red. That red color is characteristic of the chromosphere.

ChrisCB: Can the partial lunar eclipse, occuring this Saturday, be seen from the US?

Mitzi: Yes, but the Eastern U.S. will see little if any of the eclipse. Best viewing is west of the Mississippi River.

koodos: Can eclipses be described as alignments?

Mitzi: Yes, they can.

rahulr96: Why is a solar eclipse dangerous to look at if most of the sun's rays are blocked by the moon?

Mitzi: It's the partial phases that are dangerous to your eyes. The partial phases of a solar eclipse are still dangerous to view with the unprotected eye because the sun is SO intense. Only during totality is it safe to view the eclipse with the unprotected eye.

abishek: Can sunglasses be used during a solar eclipse?

Mitzi: No, no, no, and no! :) Again, #14 welder's glass or commercially available "eclipse glasses" should be used.

Tavish_DeGroot: Why do you think the Inca and Maya were astronomically-inclined compared to other cultures?

Mitzi: All cultures were astronomically inclined to some extent because of its importance for agricultural reasons. The Maya were similar to the Egyptians in that they built monuments which helped mark specific dates and times -- again, important for agriculture. The Inca built magnificent dwellings that were not only for astronomical purposes, but for everyday use. Some of their structures were indeed used from astronomical predictions. In the case of the Maya, they lived close to the equator and had opportunities to view the sun directly overhead a couple of times a year -- which is important if you're relying on the sun for your lifestyle. So that may be one reason -- these cultures were close to the equator and the sun was dominant in their lives.

starman: Is it safe to look through a camera's lens to get a picture of the solar eclipse?

Mitzi: NO. NO. NO. NO. :) ONLY look through a device which as a special solar filter attached in FRONT of its optics.

(Moderator Jason): We're still working on answering all the great questions you've asked. If you haven't seen yours yet, give us a few minutes to get to all of your questions. To submit your own question, please type it in the box at the bottom of the window and click the 'Ask' button on the right side of the box. Thanks for your patience as we answer your questions.

tlwm: Do you plan or have a solar satelite in in a moon stationary (I mean fixed in eclipse position) orbit?

Mitzi: There are currently many solar satellites which are observing the sun. SOHO, STEREO, SDO, Hinode -- these observe the sun from many different places and they can observe the corona at all times in visible (white) light and in X-rays.

abishek: What part of our eye will be affected during a eclipse?

Mitzi: It could be the retina -- too much light can be focused onto the retina and burn a hole in it.

Cosmonaut: How did ancient cultures such as the Celts or Aztecs, react to solar/lunar eclipses?

Mitzi: Not sure about the Celts, but the Aztecs, of course, made many human sacrifices frequently, so they would have sacrificed as a result of solar or lunar eclipses. The Incas beat their dogs and yelled and screamed. They weren't capable of predicting the eclipses, but the Maya and Aztecs could.

unclec: At what time will Saturday's lunar eclipse begin in the southeast US?

Mitzi: The lunar eclipse will be at maximum eclipse right around daybreak. Unfortunately, to the Southeastern U.S. won't get to see very much of this one.

rolandpinto: Hey Mitzi, will the lunar eclipse be nicely visible in Northern California? Bay Area?

Mitzi: Yes, it will. Look toward the west and you should see a nicely eclipsed moon.

tlwm: Do you have a plan to move the moon to darken the Earth?

Mitzi: No. :)

summer00: Do you go to every solar eclipse?

Mitzi: No, I wish I could!

John: How do you know about Rahu and Ketu from India culture?

Mitzi: I have an interest in ancient cultures and their ideas about the Universe.

zzz_last_alphabetically: Are you ma'amm or sir?

Mitzi: I am a ma'am. :) Or I answer to "Master Mitz." hehehe!

Jon: So, basically an eclipes is were the moon comes in between the sun and the earth?

Mitzi: Yes, that's a solar eclipse.

00Arcturus00: It's possible to aprreciate, at least just slightly, the Sun's prominence during the eclipse?

Mitzi: Yes. Prominences are incredibly beautiful during a total solar eclipse. To view these well, a telescope is needed.

JJ_Jordan10: What is the strangest thing you have observed during an eclipse?

Mitzi: There wasn't anything particularly strange, but a teacher friend who went with me to Zambia became so excited that she forgot to shoot the video and record the eclipse!

Tavish_DeGroot: Did ancient cultures understand how to develop ways to dim the received light from the sun so that they could safely look at it?

Mitzi: Yes. Actually in some records, the Chinese observed sunspots by looking at reflections in pools of water.

Tavish_DeGroot: Is your interest in the astronomical inclinations of the Maya and Inca civilizations a merging of interests in astronomy and ancient culture, or did one interest grow out of the other?

Mitzi: Yes to both :)

abishek: Ma'am, you said to akarsh that there are cosmic rays, too.

Mitzi: Cosmic rays continually bombard the solar system. They're deflected by the solar magnetic field, which is stronger during solar maximum. We now have few sunspots, and the sun's magnetic field isn't very strong, so we have a lot more cosmic rays that can impact Earth and the rest of the solar system.

abishek: Ma'am, do you enjoy being here for chat?

Mitzi: Absolutely -- great questions.

Shelly: Hi there! I was wondering if any formal studies have been done regarding any corrollation between high sunspot/solar flare activity and more active seismic conditions here on earth, and the same regarding seismic activities around eclipses? I realise seismology isn't your particular field, but this has been something I've been paying attention to for about 15 years now and was wondering if anyone else has looked into this. Thought maybe you might have heard something about this.

Mitzi: Nothing that I know of, Shelly.

milofresco: Why can't sunglasses be used during a eclipse?

Mitzi: Because they don't remove enough of the infrared and UV.

sdluke: What is the longest solar eclipse ever?

Mitzi: Seven minutes is about the longest we can ever get.

celestialnebulae13: It's been a pleasure and such an honor to be part of this chat. :)

Mitzi: My pleasure, celestial. Thank you for the great questions.

campara: Hey Mitzi, when will be a lunar eclipse in Brazil area?

Mitzi: Try this Web site -- it's a great resource. Fred Espenak/Mr. Eclipse:

zzz_last_in_alphabetical_order: What is your favorite part about your job?

Mitzi: Doing research that no one else has done and finding answers to questions.

rahulr96: Is there any possibilty for a man made sattelite to block the sun's light and cause a miniature eclipse?

Mitzi: No, because that satellite would have to be the size of the moon or close to the size of the moon and very, very close to the Earth, which could put it into an unstable, dangerous orbit.

AkarshValsan: What is your native place?

Mitzi: I was born in Atlanta, Georgia, U.S.A. currently live in Huntsville, Alabama, U.S.A.

sdluke: At what time GMT the eclipse will happen, and which countries will be able to see it?

Mitzi: Again, this is a great Web site for that information: Fred Espenak/Mr. Eclipse:

pavcho: The Egyptians especially, knew that the sun provides us with everything we need; heat, light and life itself. Why is it that scientists, only about a month ago said that the sun MAY have a role in global warming? In addition to the solar cycles, we know that as a star goes through its life it will get hotter and bigger. Why can't we just agree that the sun is what causes the climate on earth. It does, doesn't it?

Mitzi: Scientists have only recently -- since the begining of the space age -- been monitoring the output of the sun. So, our quantitative data of the solar "constant" is only about 30 years. But climate is a very complex thing to try to predict -- and not really my field. :)

summer00: Is macchu piccu a place built for eclipses?

Mitzi: No. Machu Picchu was built most probably as a retreat for the ruling Inca peoples. The types of observations done there were typically of the Pleiades and the Tail of the Scorpion, which were indicators of solstices.

Ediz_Celik: Thanks for answering our questions :)

Mitzi: You're welcome!

Tavish_DeGroot: Just wanted to say thanks for chatting and answering our questions! =)

Mitzi: My pleasure.

AkarshValsan: Ma'am, you told to Tavish_DeGroot that Chinese observed sunspots! Was it before Galileo and David Fabricius discovered sunspots?

Mitzi: Yes, a long time before.

Josquin: What is a prominence?

Mitzi: You can see a photo of prominences on this page, but they're loops of magnetic field which enclose charged, ionized gas.

AkarshValsan: We had a luck to be in chat with you. Thank you.

Mitzi: I appreciate that -- thank you, Akarsh.

premopr: Mitzi, it's an honor to be here. I just wanna ask you, can this eclipse be seen over the middle east?

Mitzi: Thanks for coming into the chat! This Web site is a great resource for your question: Fred Espenak/Mr. Eclipse: You can see future and past eclipses here -- and where future ones will be visible.

Akarsh_Valsan: Ma'am, will you post the details of Rahu and Ketu which I posted?

Mitzi: Wikipedia also has some great information on Rahu and Ketu.

Akarsh_Valsan: Do stars cause eclipses?

Mitzi: Sort of. Sometimes stars will pass behind the moon. That's an occultation, and all types can occur: stars behind planets, stars behind the sun, etc. Sometimes Mercury and Venus pass between Earth and the Sun -- these are called transits. The next transit of Mercury is 2016, and next transit of Venus is 2012.

abishek: Mitzi, could you give us some websites related to eclipses?

Mitzi: Absoutely.

sammy: What is the Sun up to today? What is its mood?

Mitzi: It's quiet.

Shelly: I was wondering what instruments we currently have orbiting around Earth which measure magnetic changes in Earth's atmosphere when we are buffeted by higher than normal geomagnetic energy, and if anyone has proposed any way to harvest that energy and perhaps use it-whether to power satellites, re-charge shuttles(or the next generation thereof), or some other purposes? It seems to me that with huge amounts of energy due to come to us from X-class flares, this could potentially be harvested and put to use! And thanks so much for staying to answer everyone's questions!

Mitzi: Great question, Shelly, and yes, there are satellites in orbit to study the Earth's magnetic field and how it reacts to solar forcing. There have been experiments to harness the energy of the magnetic field, something called a tether. There are technical problems with tethers, but the idea is still a good one. Perhaps they could best be used in Jupiter's magnetic field, which is much stronger than Earth's now. It's difficult to harness that energy -- energy from X-class flares -- for everyday use.

premopr: What do you think about the sun activity over the past years?

Mitzi: The sun is always interesting to study, and this last solar cycle has been a surprise for everyone. The quiet, slow ramp-up to solar maximum isn't unprecedented, but hasn't been seen for 100 years.

summer00: Thank you so much for answering all my questions! I love this summer camp program thing! It's soooo cool! Goodbye :) Have an awesome day!

Mitzi: Thanks, summer -- hope to see you in other chats. Glad you're enjoying them.

Akarsh: What is penumbra and umbra?

Mitzi: Umbra simply means shadow, and the umbra of an eclipse is the deepest, darkest part of the shadow. (The umbra of a sunspot is the darkest part of a sunspot.) The penumbra is less dark.

abishek: Ma'am, when shall we chat again. Loved this one.

Mitzi: Our next chat is next Thursday, July 1. Dr. Jonathan Cirtain will talk about our solar system.

Tavish_DeGroot: What other aspects of astronomy do you study besides eclipses? What is your favorite part of astronomy?

Mitzi: I'm a solar astronomer and I study sunspots and the corona of the sun. My favorite part of astronomy is studying the sun.

(Moderator Jason): We've got time for just a couple more questions. Thanks to everyone for participating today!

zzz_last_in_alphabetical_order: Thanks for the links.

Mitzi: You're welcome.

premopr: Mitzi, I know I said that was my last question but I can't help but ask one more. Do you think the sinkholes that have happened lately have any relation to sun activity?

Mitzi: No, no relation.

zzz_last_alphabetically: It would be an honor if I could have the last question...again. Are the NASA cuts going to hinder your future eclipse research?

Mitzi: The work I'm involved with has great plans, and we expect to continue to be able to produce great results. if you have an opportunity, Google the Solar Dynamics Observatory. Much of our solar science research will use data from SDO.

JJ_Jordan10: Thank you

Mitzi: My pleasure.

Akarsh_Valsan: If you didn't become a lecturer or scientist, what option in career would you take?

Mitzi: I might have become a geologist.

(Moderator Jason): Thanks to all of you for the great questions, and thanks to our guest scientist, Mitzi Adams. Check back in the next day or two for a posted transcript of today’s chat. Have a great afternoon.

AkarshValsan: Three cheers for Mitzi Ma'am!

Mitzi: Thank you, thank you. :)

Janet Anderson, 256-544-0034
Marshall Space Flight Center, Huntsville, Ala.