Solar Eclipse FAQ

Q: What is a solar eclipse?
A: A solar eclipse is what happens when the Moon passes between Earth and the Sun, casting a shadow over our planet. During a total solar eclipse, the Moon blocks our view of the Sun completely.

Q: Are there other kinds of eclipses?
A: There sure are! A partial solar eclipse occurs when the Moon blocks just a fraction of the Sun’s rays from our line of sight, and an annular solar eclipse is what we call it when the Moon is a bit farther from our vantage point on Earth, but still passes directly between us and the Sun. Because the far-away Moon casts a smaller shadow, we can still see a ring (also called an annulus) of the Sun around the edges of the Moon.

Lunar eclipses (when we can see Earth’s shadow creeping over the Moon) come in partial and total varieties just like solar eclipses.

Q: When is the last time a total solar eclipse was visible from the United States?
A: In 1991, a total solar eclipse was visible from Hawaii. Before that, the most recent viewing opportunity in the continental United States was in 1979! And Chicago wasn’t even a city yet in 1806, the last time a total solar eclipse was visible from our little patch of the lakefront.

Q: When’s the next one?
A: After 2017, US residents will be able to see a partial solar eclipse on June 10, 2021. The next total solar eclipse to be visible from the United States will happen in 2024, and if you’re waiting to see a total solar eclipse from Chicago, you’ll be waiting a long time—until 2099, to be exact!

Q: Is it safe to look directly at a solar eclipse?
A: Only if you are in the path of totality and you wait until the Moon has completely covered the Sun. When any part of the Sun is visible, you must use protective eyewear.

Q: Do my sunglasses count as protective eyewear?
A: No, they do not! You need something a lot more powerful than your sunglasses. A pair of CE- and ISO-certified solar viewing glasses or a #14 welder’s glass will do the trick. The number 14 is the “shade number” of the glass. If you have some welder’s glass but you don’t know its shade number, do not use it. Many types of welder’s glass let in too much light for safe solar viewing.

Q: I don’t have access to special protective eyewear, but I still want to see the eclipse!
A: Don’t worry! You can view the eclipse indirectly with a pinhole projector. Poke a hole in an index card or a paper plate. Do not look through the pinhole! Instead, turn so the Sun is at your back, and hold up the card so the pinhole points toward the Sun. Then, hold up another card (or plate or piece of paper) to catch the light coming through the pinhole. This second card is your “screen,” and if you line it up right, you should see an image of the sun projected onto it. Pull it away from the pinhole to zoom in!

To learn more, check out the Adler’s safe solar viewing guidelines.

Q: Where can I see the 2017 solar eclipse?
A: If the skies are clear, a partial eclipse will be visible from the entire continental United States. The path of totality (where viewers will see the Sun completely covered by the Moon) will be a 71-mile-wide band stretching from Oregon to South Carolina. The Moon’s shadow will linger longest over a spot near Carbondale, Illinois.

Q: What do scientists study during solar eclipses?
A: Several NASA spacecraft—including SOHO, the Solar Dynamics Observatory, IRIS, and STEREO—study the Sun. Some of these missions study the Sun itself, and others also study the Sun’s outer atmosphere (also called its corona). There’s a region of the corona that all of these spacecraft miss because it’s just a little too far from the Sun for some of the instruments and too close to the Sun for others. The best time to study the entire corona is during a total solar eclipse.

Q: Where can I find educational materials related to the eclipse?

  • WGBH has assembled a folder of materials that includes a teacher toolkit to support educators in planning and integrating the eclipse into the classroom. Find maps, activities, and more.
  • The American Astronomical Society has educational resources on their eclipse website, plus a safety flyer in English and Spanish.
  • Visit NASA’s eclipse website for materials and information.
  • Search eclipseon the NASA Wavelength educational collection site.
  • The Great American Eclipse website has current and historical information about eclipses.
  • Additional resources are also available in Spanish:

Q: Is the Adler Planetarium sponsoring a trip to the eclipse path?
No, we are not offering a travel program for this eclipse, but for information about the many solar eclipse events happening in Carbondale, Illinois, visit the University’s eclipse festivities website. Carbondale, Illinois is located conveniently near Interstate 57 and is served directly by Amtrak trains several times per day, including from Chicago’s Union Station.

Where can I get solar eclipse glasses?

At Adler Planetarium

Solar eclipse glasses are no longer available with the purchase of Adler admission. To grab a pair, join us at the Adler on August 21 for Chicago’s Eclipse Fest, or at our satellite viewing party at Daley Plaza(While supplies last.) We hope you #LookUp with us!

From An Adler Brand Ambassador

As of 11:30 am, more than 1,500 people had lined up outside Lagunitas Brewing Company to get #EquippedtoEclipse! Because our offer of eclipse glasses was limited to the first 500 guests, we have opted to distribute the glasses early.

Glasses are no longer available at Lagunitas, but if you didn’t snag a pair, don’t worry! We’ll have a limited number of pairs available on Monday, and there are many other ways you can enjoy the eclipse with us. We hope to see you on Monday for Chicago’s Eclipse Fest!

At Suburban Library Branches

Several public libraries and library districts in the Chicago suburbs will be handing out eclipse glasses. Inquire with your local public library about availability. Many, but not all, of these libraries are shown on this map.

At Organizations Throughout Chicagoland

Below is a list of other organizations handing out Adler Planetarium’s solar viewing glasses, while supplies last. Each organization has created their own schedules for distribution. Please check with the organizations directly to inquire about distribution.

Important Information About Where to Purchase Glasses

A list of reputable vendors is available from the American Astronomical Society. Note that counterfeit glasses are coming in from other countries and have been on sale for some time. Just looking for the ISO certification printed on the glasses is NOT a way to tell if glasses are safe, as any vendor can print ISO certification information on their glasses. The only way to be sure your glasses are safe is to get them from the Adler Planetarium, one of our partners, and/or purchase from one of the vendors identified on the AAS web page listed above.