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When the total solar eclipse on April 8 tracks a path through Mexico, the United States and Canada, viewers can expect plenty of awe-inspiring moments.
During a total solar eclipse, the moon completely blocks the sun’s face for a short period of time, known as totality—and 32 million people in the U.S. along the 115-mile-wide (185-kilometer-wide) path of totality have the chance to enjoy this full expression of the celestial show during the event in April. Will have.
It’s worth taking a moment to stop and examine this historic celestial event because the total solar eclipse won’t be visible again in the neighboring United States until August 2044, replaced by an annular eclipse in which the moon cannot completely block the sun. It will not emerge again in this part of the world until 2046.
Dr. D., vice provost for science of the Carnegie Institution for Science and director of the Carnegie Observatories and the Crawford H. Greenewalt Chair. “It’s almost impossible to describe a total solar eclipse until you actually see it,” John Mulchaey said. “When you see the totality, you can see what a huge impact it has had on people over thousands of years. “This is one of the most beautiful things most people will ever experience.”
But eclipse experts say the phases surrounding totality are also quite memorable, including a few phenomena striking enough to deserve their own names. Here’s what you need to pay attention to.
What to pay attention to during an eclipse
The moon does not suddenly appear between the Earth and the sun; The event begins with a partial eclipse in which the moon appears to take a “bite” from the sun. Depending on your location, the partial eclipse could last between 70 and 80 minutes, according to NASA.
For those living outside the path of totality, the main event will be a partial crescent-shaped eclipse rather than a total eclipse.
The partial eclipse is the longest phase in the path, but look for changes in the sky’s appearance as the time of the total eclipse approaches.
“About 15 to 20 minutes before totality, the sky starts to take on a really weird, gloomy color,” Mulchaey said. “It almost looks gray because the sun is so high in the sky but it’s almost completely blocked. It’s not like dusk, sunset or sunrise when the sun is low. He’s on you. And all of a sudden you lose a lot of the sunlight and it feels so weird.”
The eerily darkening sky is a sign to skywatchers that the star show is about to begin. Make sure you have your solar eclipse glasses with you to see the sun safely before the event starts.
Mulchaey said two breathtaking phases occurred in the final moments before totality.
As the Moon begins to pass in front of the Sun, the star’s rays will shine around valleys on the moon’s horizon, creating bright blobs of light around the moon called Baily beads. This phenomenon is named after British astronomer Francis Baily, who observed it during the annular eclipse of May 15, 1836.
As totality approaches, Baily’s beads will quickly disappear and be replaced by a “diamond ring,” a nickname for what it looks like when a single point of light remains—like a giant sparkling diamond ring.
Both of these stages take less than a minute, Mulchaey said.
Then it’s time for integrity.
Prepare for wholeness
The totality phase of the eclipse on April 8 is expected to last twice as long as in 2017 due to the Moon being closer to the Sun at this time. According to NASA, those along the path’s centerline will see a total eclipse that will last 3½ to 4 minutes.
“All of a sudden totality occurs and corona appears,” Mulchaey said. “Even though it’s dark outside, it’s somehow gorgeous.”
The corona is the sun’s extremely hot outer atmosphere that emits a glow that can be seen around the moon during an eclipse. Typically, the corona is difficult to see because the surface of the sun is much brighter. According to NASA, during a total eclipse the corona will resemble streams of white light.
During the 2017 eclipse, the sun was approaching solar minimum, the quiet phase of our star’s 11-year activity cycle. The sun is approaching solar maximum at this time, when the sun is extraordinarily active, Mulchaey said. The corona will likely appear brighter and fuller, and there may be a chance to detect glowing cycles of solar activity that resemble ribbons within the corona during the eclipse.
Viewers will also be able to see a region of the sun’s atmosphere called the chromosphere, which will appear as a thin, pink circle around the moon.
Bright stars or planets such as Venus may shine in dark skies, and air temperatures may drop when the sun disappears. Sudden darkness also causes animals to behave in unusual ways.
Visiting the Cornell Laboratory of Ornithology, scientist Dr. Andrew Farnsworth writes, “The chirping of crickets.” chirping (chirping) or the emergence of bats “We may start to see that animals are coming out and stopping their daytime behaviors (like birds perching or flying insects landing on the ground),” he said.
After totality ends, the diamond ring and Baily’s beads will reappear briefly as the moon slowly moves in front of the Sun, before the partial eclipse returns.
Why do eclipses occur on Earth?
Just six years after the total eclipse passed over the United States, the path of the April 8 eclipse is very different; walking from west to east.
On average, an eclipse occurs in the same location every 375 years, Mulchaey said.
“And we’re living at the right time to really enjoy watching the total eclipse on Earth,” he said.
Although eclipses occur throughout the solar system, none of them are exactly like those experienced on Earth.
The Moon is about 400 times smaller than the Sun, but the Moon is also about 400 times closer to the Earth than the Sun, creating a “beautiful coincidence” that results in eclipses when the three celestial bodies align, Mulchaey said.
This alignment is called syzygy, or the alignment of three objects in space.
In the distant past, the Moon was much closer to Earth, meaning that the totality probably did not appear as much as it does now. Mulchaey said that in the next 60 million years, the Moon will be so far away that it will never block the Sun, which will be a rare moment.
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