The biggest skywatching event of 2019 has finally arrived! Beginning today (July 2) at about 3:22 p.m. EDT (1922 GMT), the moon's shadow will darken skies over a narrow strip of land through Chile and Argentina as Earth's natural satellite passes in front of the sun in the first total solar eclipse to grace our planet since the Great American Solar Eclipse of Aug. 21, 2017 (opens in new tab).
Today's relatively rare celestial event, which some have dubbed the "Great South American Eclipse," will be visible to skywatchers across almost all of South America, though most of the continent will only witness a partial eclipse.
But the best part of the show will occur in the path of totality (opens in new tab), a 125-mile-wide (200 kilometers) band stretching from La Serena, Chile, to just south of Buenos Aires, Argentina. Here, skywatchers will be treated to up to about 2.5 minutes of daytime twilight as the moon completely blocks the sun from view — with the exception of its wispy corona (opens in new tab), which is only visible during total solar eclipses.
While a few remote islands in the Pacific Ocean will be the first to see today's eclipse, the main part of the show will begin once the moon's shadow reaches the west coast of Chile near the city of La Serena.
The moon will first begin to creep in front of the sun for skywatchers in La Serena beginning at 3:22 p.m. EDT (1922 GMT). It will slowly encroach farther onto the sun's disk until 4:38 p.m. EDT (2038 GMT), when totality begins. For 2 minutes and 18 seconds, La Serena will be in the moon's shadow, offering skywatchers a rare glimpse of the sun's corona. After the total phase of the eclipse ends, the moon will slowly glide out from in front of the sun, and the partial solar eclipse (opens in new tab) will end at 5:46 p.m. EDT (2146 GMT).
From there, the moon's shadow will head southeast across the Andes Mountains and toward the Atlantic Ocean, narrowly missing the city of Buenos Aires near the border of Argentina and Uruguay. On the east coast of South America, the eclipse will end just after sunset.
Although only a small slice of South America will experience a total solar eclipse, much of the rest of the continent will at least see a partial eclipse. If you're planning to watch the partial eclipse, you'll need to wear eclipse glasses whenever you're gazing at the sun to avoid longterm or even permanent damage to your eyes (opens in new tab).
While you should never look at the sun without protective eclipse glasses (opens in new tab), totality is the one exception to that rule. Because the sun is hiding behind the moon, you don't need to worry about burning your eyes for that brief moment in time. In fact, if you don't remove your eclipse glasses during totality, you won't be able to see anything at all. Just remember to put them back on as soon as totality ends.
If you're not in the path of totality — or if an inconsiderate cloud ends up blocking your view of the eclipse — you can still watch the eclipse live online. Several observatories and institutions will be streaming live views of the eclipse, and you can find a list of eclipse webcasts here (opens in new tab). Most webcasts all start around 3 p.m. EDT (1900 GMT) and last until the last partial phase of the eclipse ends around 6 p.m. EDT (2200 GMT).
As for the cloud situation, luckily the weather forecasts are predicting clear skies (opens in new tab) throughout the path of totality. In places where only a partial eclipse is visible, particularly in the southern and northern extremes of South America, there's a chance that clouds could get in the way. If that happens and you can't see the eclipse during totality, you may still be able to spot some stars and planets (opens in new tab) that are otherwise invisible in daylight.
Another option, if you're determined to see the eclipse but happen to be in a place where the weather does not look promising, is to pack your bags and hit the road as soon as possible to drive to a place with clear skies in the forecast. If you are planning a last-minute road trip, whether you're fleeing clouds or heading to an event, be sure to leave early. You probably don't want to be stuck in a car on the highway when totality arrives. This one may go without saying, but please do not try wearing eclipse glasses while driving. Be safe, pack plenty of water and snacks, make sure your car has enough gas, and go chase that eclipse!
Editor's Note: If you snap an amazing picture of the July 2, 2019 total solar eclipse and would like to share it with Space.com's readers, send your photos, comments, and your name and location to firstname.lastname@example.org.
- How to Film or Photograph the 2019 Total Solar Eclipse Like a Pro (opens in new tab)
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- Can You Reuse Eclipse Glasses from 2017? (opens in new tab)