On April 8, North Americans will catch sight of the total solar eclipse, when the moon will pass between the sun and earth, completely blocking sunlight for up to 4 minutes and 28 seconds.
Viewers across 15 U.S. states, Canada, and Mexico will be able to observe the sun’s outer crownlike atmosphere, known as the corona, which is usually hidden by the bright light of the sun’s surface. The glowing white corona will be visible surrounding the eclipsed sun (see picture above).
The Total Solar Eclipse Returns…But Looks Different this Year
Did you catch the last solar eclipse seven years ago? NASA reports that in 2017, an estimated 215 million U.S. adults (88% of U.S. adults) viewed the solar eclipse, either directly or electronically. While we prepare for the sight, the agency examines how this year’s solar event will be different. The 2024 eclipse will pass over more cities and densely populated areas than in 2017, and the spectacle will also last about a minute or two longer, depending on where you live.
Scientific research dedicated to the solar event has also expanded this year: NASA will fund five interdisciplinary science projects for the 2024 eclipse. The agency reports that the projects are led by researchers at different academic institutions and research will focus on the sun and its influence on earth with “a variety of instruments, including cameras aboard high-altitude research planes, ham radios, and more.” A portion of the projects also encourage participation from citizen scientists.
Setting Your Sights on Solar with Caution
An estimated 99% of people who reside in the United States will be able to see the partial or total eclipse from where they live in April. In light of the solar event, the American National Standards Institute (ANSI) reminds solar eclipse onlookers to proceed with caution during your viewing session. Onlookers can prepare with safety in mind by using “eclipse glasses” that comply with ISO 12312-2, Eye and face protection-sunglasses and related eyewear-Part 2: Filters for direct observation of the sun. Unlike your regular everyday shades, eclipse glasses effectively filter out the portions of the solar spectrum that could injure eyes.
ANSI is the U.S. member body to ISO, and ANSI member and audited designator ASTM International serves as the ANSI-accredited U.S. TAG administrator to the ISO Technical Committee (TC) 94, Subcommittee (SC) 6, Eye and Face Protection, which supported the development of ISO 12312-2.
As ANSI reported during the previous total solar eclipse, be cautious of fake eclipse shades: Many counterfeit eclipse viewers stamped with the ISO logo and certification label can be sold to unsuspecting customers via e-commerce and other retailers. To avoid falling victim to a solar shade scam, the American Astronomical Society (AAS) Solar Eclipse Task Force has compiled a list of acceptable companies on its Reputable Vendors of Solar Filters & Viewers page and a list of what to look for when purchasing eclipse glasses.
Want to learn more? ANSI member The Vision Council has published a Total Solar Eclipse Guide, offering information on safe viewing in addition to photography tips, the eclipse’s path with cities and times, an eclipse-themed playlist, and more.
Happy viewing! If you miss out on this one, the next total solar eclipse that can be seen from the contiguous United States will be on August 23, 2044.