[Last updated: Monday, Aug. 21 at 1:35 p.m.]
If you're hoping to view today's historic solar eclipse, you're going to need a pair of specialty sunglasses affixed with a solar filter. But -- as we mentioned -- that eclipse is today. That means you have just hours to score a pair if you haven't yet.
And they've been notoriously difficult to nab.
The American Astronomical Society maintains a list of reputable vendors for glasses with the appropriate filter. Official glasses should have language printed on them indicating they were built to "conform to the transmission requirements of ISO 12312-2" and "Filter for Direct Observation of the Sun."
Where around the D.C. area can you find glasses? That information changes every day (perhaps every hour), but here's what we know as of Monday morning. (NOTE: You might want to call ahead or be prepared to go to several spots before scoring your own pair, so pack your patience.)
NEW: Smithsonian's National Zoo: We just learned the zoo will be giving out 3,500 pairs of free glasses at their eclipse event Monday near the elephant house.
National Air and Space Museum, National Mall location: The museum hands out a limited number of glasses each day. On Monday, the museum is planning to hand out several thousand pairs.
The museum will also offer several educational programs Monday, including a solar eclipse viewing event, complete with free glasses handed out all day, according to the Smithsonian's newsroom. The museum will also have safe solar telescopes available from 1 to 4 p.m. on the day of the eclipse, along with a table to make your own pinhole eclipse viewer from 11 a.m. to 4 p.m.
National Air and Space Museum, Steven F. Udvar-Hazy Center: The museum's Northern Virginia location is also handing out a limited number of glasses daily, starting at 10 a.m. When we last called Saturday, they were already out as 3 p.m. On Monday, the museum intends to hand out several thousand pairs.
National Museum of the U.S. Navy, Washington Navy Yard: The Naval Research Laboratory (NRL) will host an eclipse viewing event Monday, where they will hand out glasses to the first 100 attendees.
Prince George's County Memorial Library System: You need to attend one of these libraries on the day of the event in order to receive a free pair of viewing glasses. However, children ages 5 to 12 will receive priority. Libraries with viewing parties are located in Beltsville, Bowie, Glenarden, Hyattsville, Hillcrest Heights, Largo-Kettering, Laurel, Oxon Hill and Upper Marlboro.
Anne Arundel County Public Library, Maryland: Glasses will be provided here during their solar eclipse viewing party Monday, but note that they have a limited number of glasses and cannot guarantee them for all attendees.
Arlington Public Library, Virginia: Arlington Public Library's web page now has a banner stating "No Solar Eclipse Glasses at Any Library Location."
Chevy Chase Library, Maryland: The library will host a viewing party for the eclipse Monday with free glasses -- but registration is full, they said Monday. The library will also be streaming the event live from their meeting room.
Montgomery County Libraries, Maryland: The library system is out of glasses.
Montgomery County Parks, Maryland: You can attend a watch party -- appropriately called Total Eclipse in the Park -- at Martin Luther King Jr. Recreational Park in Silver Spring, Maryland from 1 to 4 p.m. Monday. The park has 600 pairs of glasses to distribute at the event, but they expect supplies to run out quickly.
Adroit Theory Brewing Company in Purcellville, Virginia, was offering free viewing glasses with the purchase of a bottle, but they ran out within an hour of opening Monday. You can still bring your own glasses and get 50 percent off growler fills, they said on Twitter.
Warby Parker: The popular eyewear retailer handed out free pairs of solar eclipse glasses earlier this month, but all local stores are now out of stock. The Bethesda location did hand out another 100 pairs Monday morning -- but those are all snapped up now. The retailer is offering a downloadable guide on making a pinhole projector.
Many other stores, such as Walmart and Lowe's, were selling the glasses for around $1 to $2 a pair, but have been selling out quickly. Earlier this month, NBC Washington intern Allison Pecorin was able to find a pair at a Walmart in Alexandria, Virginia, after calling several stores in the area.
If all else fails, NASA's Jet Propulsion Laboratory has a guide to making your own pinhole camera for safely viewing the solar eclipse. All you'll need is two pieces of white card stock, aluminum foil, tape and a pin or paper clip.