Eclipses happen due to an amazing cosmic coincidence that means the moon appears as large as the sun<\/p>\n
Chancey Bush\/The Albuquerque Journal via AP<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
People travel thousands of miles to see eclipses. There\u2019s nothing quite like the darkness that descends and the excitement that ripples through the crowd. A\u00a0total solar eclipse\u00a0will soon grace the skies across parts of Central and North America, with some locations outside the path of totality able to see a partial eclipse of the sun. So now is as good a time as any to ask: what exactly is a solar eclipse?<\/p>\n
When one celestial body is obscured from view by another body that moves in between, astronomers refer to the event as an \u201coccultation\u201d. Technically, total solar eclipses are occultations of the sun by the moon.<\/p>\n
A total solar eclipse happens when the moon and sun line up perfectly, such that the moon moves in front of the sun and blocks out nearly all of its light. When viewed from the path of totality \u2013 the stretch of Earth that will see the total eclipse \u2013 the sun all but disappears. This part of an eclipse can last for up to 7.5 minutes. The 8 April eclipse will last 4 minutes and 27 seconds.<\/p>\n
What causes a solar eclipse?<\/h2>\n
<\/p>\n There are many kinds of solar eclipse, but each happens when the moon passes in front of the sun, blocking out some or all of its light as viewed from a specific part of the planet. By sheer cosmic coincidence, the moon and the sun appear the same size in the sky because the moon is about 400 times as small as the sun, but the sun is about 400 times as far away. When the two line up perfectly during the new moon lunar phase \u2013 when the moon sits between Earth and the sun \u2013 the moon can block out the entirety sun\u2019s light. This is a total solar eclipse.<\/p>\n During an eclipse of the sun, the moon casts two shadows. The middle part of the shadow, where no light reaches, is called the umbra. The outer partial shadow is known as the penumbra; here, only light that has come from part of the sun\u2019s disc can reach. During a total eclipse, the path of totality is the stretch of land within the umbra. On 8 April, this path will be 185 kilometres wide, stretching across North America from Mexico, through the US and Canada. But the path of totality can be as narrow as 150 kilometres. The penumbra covers a much greater area, and in those places viewers will be able to see a partial solar eclipse.<\/p>\n NASA Goddard Space Flight Center Conceptual Image Lab<\/p>\n<\/div>\n<\/figcaption><\/figure>\n A partial eclipse happens when the moon just blocks out a portion of the sun\u2019s light. This occurs when\u00a0 viewers are within the penumbra. Before and after totality, viewers can see the moon slowly encroaching on the sun in a partial eclipse. But there are also times when only a partial eclipse is visible from anywhere on Earth because the moon\u2019s central shadow misses our planet completely.<\/p>\n An annular solar eclipse happens when the moon\u2019s elliptical orbit puts it closer to Earth than usual, so it obscures most of the sun\u2019s light but leaves what is known as a ring of fire. Hybrid eclipses occur when a total eclipse is visible from some parts of the world, but an annular eclipse is visible from others. Total, hybrid and annular eclipses are all types of \u201ccentral\u201d eclipse, meaning the umbral shadow is cast somewhere on Earth.<\/p>\n On 8 April a total solar eclipse will pass over Mexico, the US and Canada. Our special series is covering everything you need to know, from how and when to see it to some of the weirdest eclipse experiences in history.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/section>\n Each year, between two and five solar eclipses are visible somewhere around the world. Total solar eclipses happen, on average, every 18 months. But for a given spot on the planet, total eclipses of the sun are only seen every 400 years or so, since the portion of Earth from which each total eclipse is visible is so small.<\/p>\n A lunar eclipse happens when the moon moves through the shadow Earth casts into space. These events always occur during the moon\u2019s full phase, when the moon is on the opposite side of the planet from the sun. But they don\u2019t happen every full moon, because our moon\u2019s orbit is tilted around the Earth compared to Earth\u2019s orbit around the sun.<\/p>\n Since eclipses are caused when the Earth, sun and moon line up in a row \u2013 in what is called syzygy \u2013 a solar eclipse is always accompanied by a lunar eclipse, either two weeks before or after. This year there will be a lunar eclipse on 24 March, two weeks before the 8 April solar eclipse. But it will be a penumbral lunar eclipse, meaning only Earth\u2019s outer shadow will obscure the moon.<\/p>\n Topics:<\/p>\n![\"New](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/02\/27185455\/solar_eclipse4k_prores_30fps-ezgif.com-optimize-1.gif?width=1200\")
<\/div>What are the different kinds of solar eclipse?<\/h2>\n
![\"ER8EXD](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/02\/27195123\/SEI_193518799.jpg?width=300\")
<\/picture>\nSolar Eclipse 2024<\/h3>\n
How often do solar eclipses occur?<\/h2>\n
What is a lunar eclipse?<\/h2>\n
Do eclipses always come in pairs?<\/h2>\n