This weekend, millions of people will feast their eyes on the latest celestial marvel: an annular solar eclipse gracing the skies of the Western Hemisphere.
The “ring of fire” eclipse will begin in Oregon on Saturday morning, sweep across the American Southwest and exit the United States through Texas. It will cut through the Yucatán Peninsula in Mexico and cross a number of Central American countries before reaching South America. There, it will pass through Colombia and Brazil, and end its run over the Atlantic Ocean.
We’ll say this twice in this article: Remember to never look directly at a partial eclipse — wear protective eyewear or use an alternative viewing method to protect your eyes.
What is an annular solar eclipse?
A solar eclipse occurs when the moon is positioned in just the right spot between the sun and the Earth to block the sun from our view. When this happens, part of the Earth bathes in lunar shadow. It is a natural coincidence that the sun and the moon appear to be the same size in the sky. Though the sun is roughly 400 times as big as the moon, it is also about 400 times as far away from Earth.
The moon’s orbit is not a perfect circle, but slightly elliptical. An annular solar eclipse happens when the moon is at its farthest point from Earth, or apogee. That makes it appear slightly smaller than the sun. During full annularity, or the maximum phase of the eclipse, the size differences make visible an orange halo around the moon — the so-called “ring of fire.”
By contrast, a total solar eclipse happens when the moon is close enough to Earth to fully block the sun, making the sky go dark as night. During an annular eclipse, the sky dims to look like it does at dusk.
Where can I see the annular solar eclipse?
The best places to see the eclipse are along the path of annularity, at locations that lie within the shadow of the moon during this time. The New York Times has published a map that shows the solar eclipse’s approximate path. Some cities in the United States on or near this path are Eugene, Ore.; Ely and Battle Mountain in Nevada; Richfield, Utah; Roswell and Albuquerque in New Mexico; and cities in Texas like Midland, San Antonio and Corpus Christi.
Notable American landmarks along the path of annularity include Crater Lake in Oregon, Chaco Canyon in New Mexico and Lava Beds National Monument in California. The eclipse will also pass over the Four Corners — where Utah, Colorado, New Mexico and Arizona intersect — though some of this land will be closed to accommodate traditional Indigenous beliefs.
Outside of the United States, cities that will experience annularity include Campeche and Chetumal in Mexico; Belize City, Belize; Olanchito, Honduras; Cali, Colombia; and Tefé and João Pessoa in Brazil.
Many major cities are not in the path of annularity, but will experience a significant partial eclipse. They include Seattle, Los Angeles, Las Vegas and Houston in the United States, as well as Mexico City, Bogotá in Colombia, Rio de Janeiro and Tegucigalpa, Honduras.
The Times and its reporters will provide dispatches from locations along the length of the eclipse, both in the United States and around Latin America.
When does the annular eclipse begin and end?
The eclipse will start over the Pacific Ocean, 1,200 miles northwest of the U.S. mainland, at dawn.
A partial solar eclipse will be visible in Oregon as early as 11:05 a.m. Eastern time. There, annularity will occur around 12:16 p.m. and sweep across the nation for the next couple of hours. The annular eclipse will cross over the Texas coastline around 12:58 p.m. Eastern time. It enters Mexico around 1:21 p.m. and passes over Central and South America for over two hours before ending on the coast of Brazil at 3:48 p.m. Eastern time.
How long the annular eclipse lasts depends on the location it is viewed from. In the United States, people on the coast of Texas will experience annularity for the longest stretch, about five minutes. But viewers on the Nicaraguan and Panamanian coasts will see the longest duration across the Americas, for about five minutes and 15 seconds.
What if I can’t get to the path of annularity?
People outside the path of annularity will experience a partial solar eclipse. Only a portion of the sun will be hidden by the moon, leaving a glowing gold crescent in the sky. Less of the solar surface will be covered by the moon as you move further from the path of annularity.
If weather or other restrictions prevent you from seeing the eclipse in person, several organizations are hosting livestream events of the annular eclipse, including NASA, Time and Date, the San Francisco Exploratorium and Lowell Observatory in Arizona.
What do I need to see the eclipse?
A popular, inexpensive option is to purchase paper eclipse glasses, which filter out harmful solar radiation. There are also eclipse viewers that come with magnification to enhance your view of the sun. Be wary of faulty eclipse glasses. The American Astronomical Society maintains a list of reputable vendors to check before you buy.
According to NASA, you should avoid using eclipse glasses that are in any way damaged, so be careful if you have viewers left over from the Great American Eclipse of 2017. The space agency also recommends not looking at the sun through a camera lens, telescope or other optical device while wearing eclipse glasses to avoid burning through the protective filter.
More expensive viewing options include binocular or telescope filters.
If you can’t get your hands on special gear, you can watch the annular eclipse indirectly using a pinhole camera. This can be as simple as making a crisscross pattern with your fingers or punching a hole in an index card to see an image of the eclipse projected onto the ground. For a more sophisticated option, you can make a box pinhole projector using common household items.
What will happen during the annular eclipse?
The event will begin with a partial solar eclipse, as the moon slowly engulfs the surface of the sun. This phase, called first contact, will last around one hour and 20 minutes, according to NASA.
The second contact phase is annularity, when the sun will appear as a ring of fire in the sky. Around 90 percent of the solar surface will be obscured by the moon for one to five minutes, depending on the viewing location. During this phase, the sky will darken, animals may be confused and plants might hunker down.
After annularity, the moon will slowly creep away from the sun, creating another partial solar eclipse. This third contact phase will last another hour and 20 minutes. At fourth contact, when the sun is fully revealed again, the eclipse will have ended.
How frequently do solar eclipses occur?
According to NASA, the sun, moon and Earth only line up for a total or annular solar eclipse twice a year. But many happen in other parts of the world or over water, and can be difficult to observe.
In the United States, the last annular eclipse occurred in 2012, and the last total solar eclipse happened in 2017. If you miss the annular eclipse this weekend, a total solar eclipse will start in Mexico, travel through the Eastern half of the United States and end in Canada next April.
After 2024, the next solar eclipse won’t be seen in the United States until 2041.
Is it worth the hype?
Spectators have described a solar eclipse as a spiritual experience. Eclipse chasers — people who travel the world to feel the fleeting moments of awe that the celestial event inspires — claim their first time changed their life forever.
The only way to know is to see it yourself.
