by On August 21, 2017, a total solar eclipse moved from the Pacific to the Atlantic, casting a narrow path through 14 U.S. states under the moon’s shadow in the first coast-to-coast totality in 99 years. That day, the shadow moved from Oregon across the US to South Carolina, roughly northwest.
It’s about to happen again, with the total solar eclipse on April 8 starting again in the Pacific Ocean and ending in the Atlantic, but this time, the path seems to go from southwest to northeast.
There are other differences as well, including the maximum length of totality (2 minutes 40 seconds in 2017 and 4 minutes 28 seconds in 2024) and the width of the path of totality (about 70 miles in 2017 and about 115 miles in 2024). This time around, millions more people will suffer altogether – and at a time when the sun near solar maximum.
Related: Total solar eclipse April 8, 2024: Live updates
Here’s how the 2024 total eclipse differs from the 2017 total eclipse:
Eclipse Circumstances
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“The eclipse circumstances are completely different,” said Dan McGlaun, an eclipse expert at Eclipse, 2024which is the interactive map and eclipse simulator for the upcoming eclipse, in an interview with Space.com.
“It’s all because of the distance to the sun and the moon — just simple geometry.” Although the distance from the Earth to the sun varies — it is the closest to it perihelion in January and furthest away at aphelion in July – that doesn’t affect the two eclipses because the sun is about the same distance away.
What is very different is the distance from Earth to the moon, which has a slightly elliptical orbit.
The distance to the moon
During the peak of the 2017 eclipse, the moon was 231,155 miles (372,008 km) from World, and on April 8, it will be 223,392 miles (359,515 km) away. On April 8, the moon will be a few thousand miles closer, so its conical shadow that falls on Earth will have a larger diameter. In 2017, the path of totality was between 62 and 71 miles wide, according to NASAand on April 8, it will be between 108 and 122 miles wide, covering much more of the Earth.
The path of totality – a projection of the moon’s shadow – moves from west to east so that is the direction the moon orbits the Earth (and the moon travels much faster than the Earth rotates, visibly overtaking during the eclipse). Partially cancel out the speed of the moon, but its shadow will remain swept across the Earth from west to east at more than 1,500 miles (2,400 km) per hour on April 8, according to NASA.
The position of the moon
The Moon’s orbital path around the Earth is inclined by 5.1 degrees with respect to the Earth’s orbit around the Sun. That means their orbit crosses the ecliptic – the sun’s apparent path through our sky during the day – at two points, which astronomers call nodes (ascending and descending). When he does so at a New mooncauses a solar eclipsebut the node at which it occurs makes a difference.
“An ascending node eclipse is the moon going up and a descending node eclipse is going down,” McGlaun said. However, since both 2017 and 2024 are ascending node eclipses, there is something else that is much more important when looking at the different paths – the angle of the Earth.
The Rotation of the Earth
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The sun and the moon come together to create a shadow in the ever-present space. A path of totality is created when a retrograde planet at 23.4 degrees finds its way. “As the year progresses, the Earth changes its orientation and rotates in place, and this, more than anything else, is why the shadow in 2017 is different from 2024,” said McGlaun. In short, the Earth’s axis is tilted in different directions during the two eclipses.
“In 2017, it’s the Earth rotating during totality that makes that path look like it’s going down, but it’s actually going up,” McGlaun said. As seen from the sun, North America appears to be moving up the globe as the Earth rotates during the eclipse, as you can see on McGlaun solar eclipse simulator. “For the 2024 eclipse, the moon’s shadow is doing the same thing, but the Earth is following the other way.” During the eclipse, North America appears to be moving down the globe as the Earth rotates.
Change the angle of the Earth’s axis, and you can place the path of totality anywhere you want.
‘Eclipse Crossroads’
Another consequence of all this is that the paths of 2017 and 2024 cross, creating an “Eclipse Crossing” area of about 9,000 square miles (14,500 square km) in parts of southeastern Missouri, southern Illinois and western Kentucky that will soon experience the second whole i. less than seven years.
The center lines cross in Makanda, Illinois, near Carbondale. Also in the lucky quarter are Paducah, Kentucky, Cape Girardeau and Farmington, Missouri. Meanwhile, the 14,000-square-mile (36,000 sq km) “Eclipse Crossroads” region of the Texas Hill Country — centered on Vanderpool — is where the Oct. 14 annular “ring of fire” solar eclipse was just a warm-up for the Public. full to come.
The solar cycle
Another major change between 2017 and 2024 is the sun’s magnetic activity. The sun has its own cycle, the solar cycle, which lasts about 11 years. During that time, its magnetic activity decreases and decreases. The 2017 eclipse occurred near solar minimum when magnetic activity was low. Solar maximum is predicted to occur in 2024, which means more of the sun will be visible during the eclipse.
Use your eclipse sunglasses during the partial phases of the eclipse, and you will see sun spots — dark areas of magnetic activity — on the surface, near its equator. If you are in the path of totality, totality will likely reveal a larger crown, burns throughout the crown and visibility, which can be seen as bright, pink curls or loops coming out of the sun.
