10 things you probably didn't know about the 2024 total solar eclipse

关于2024年日全食你可能不知道的10件事

On April 8, 2024, North America will experience the world's longest land-based total solar eclipse in over a decade.

2024年4月8日，北美将经历十多年来世界上最长的陆地日全食。

The path of totality will cross parts of four states in Mexico, 15 U.S. states, and five Canadian provinces, allowing around 40 million people to witness the celestial spectacle.

日全食的路径将穿过墨西哥的四个州部分地区、美国的15个州和加拿大的五个省，使得大约4000万人能够目睹这一天文奇观。

You can watch the total solar eclipse live here on Space.com. And keep up with all the actions with our total solar eclipse 2024 live updates blog.

您可以在Space.com上实时观看日全食。请继续关注我们的2024年日全食实时更新博客，了解所有动态。

But how much do you know about it? From exactly how long the moon's central shadow will move across the planet to why the event will repeat for hundreds of years — and one day return to North America — here are ten facts that may surprise you.

但是您对它了解多少呢？从月球中心阴影将在地球上移动的确切长度，到为什么这一事件将重复数百年——并且有一天将返回北美——这里有十个可能会让您感到惊讶的事实。

Related: Why April's total Solar Eclipse will bring unique views of the sun's corona

相关：为什么四月的日全食将带来独特的日冕景观。

After the moon's central shadow touches the Earth at sunrise in the Pacific Ocean close to Starbuck Island in Kiribati, it will take 3 hours and 16 minutes to cross the Earth before it departs at sunset in the Atlantic Ocean north of the Azores.

当月球中心阴影在太平洋日出时接触地球，靠近基里巴斯的星巴克岛后，它将花费3小时16分钟穿越地球，然后在亚速尔群岛北部的大西洋日落时离开。

The path of totality will be about 10,000 miles (16,000 kilometers) long, less than half of which occurs on land. Totality will move across North America — Mexico, the U.S. and Canada — in 100 minutes, spending 68 minutes moving across parts of 15 U.S. states.

日全食的路径将长达约10,000英里（16,000公里），其中不到一半是在陆地上。日全食将在100分钟内穿越北美洲——墨西哥、美国和加拿大——在15个美国州的部分区域移动68分钟。

For those within the path of totality, it will bring the longest totality on land (4 minutes 28 seconds) since the total solar eclipse on July 11, 2010, in Easter Island/Rapa Nui.

对于那些位于日全食路径内的人来说，这将是自2010年7月11日在复活节岛/拉帕努伊发生日全食以来，陆地上最长的日全食（4分钟28秒）。

If you saw the annular solar eclipse on October 14, 2023, through eclipse glasses, and you're considering giving this one a miss, think again. This is a total solar eclipse, where the moon will briefly cover the entire disk of the sun.

如果您在2023年10月14日通过日食眼镜观看了环形日食，并且您正在考虑错过这一次，请重新考虑。这是一次日全食，月球将短暂地覆盖太阳的整个圆盘。

Only during this kind of solar eclipse can the sun's outer corona be seen with the naked eye—it's like seeing our star for the first time, floating in space, and it's guaranteed to leave you a gibbering wreck.

只有在这种日全食期间，人们才能用肉眼看到太阳的外层日冕——这就像是第一次在太空中看到我们的恒星，它保证会让你激动得说不出话来。

REMEMBER to NEVER look at the sun directly. To safely view this solar eclipse you must use solar filters. Only during the exact moment of totality, when the moon completely obscures the sun can you look with the naked eye. At all other times, precautions need to be taken. Observers will need to wear solar eclipse glasses, and cameras, telescopes and binoculars must have solar filters placed in front of their lenses.

请记住永远不要直视太阳。要想安全地观看这次日食，您必须使用太阳滤镜。只有在日全食的确切时刻，当月球完全遮挡住太阳时，才能用肉眼观看。在其他所有时间，都需要采取预防措施。观察者需要戴上日食眼镜，相机、望远镜和双筒望远镜的镜头前都必须安装太阳滤镜。

Related: Best solar viewing kit 2024: Observe the April 8 solar eclipse

相关：2024年最佳太阳能观察套件：观察4月8日的日食。

About 115 miles wide as it races across Earth's surface, the path of totality will cross parts of four states in Mexico (Sinaloa, Nayarit, Durango and Coahuila), 15 U.S. states (Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Tennessee, Michigan, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire and Maine) and seven Canadian Provinces (Ontario, Quebec, New Brunswick, Prince Edward Island, Nova Scotia and Newfoundland). In the U.S., totality will begin in Texas at 1:27 pm CDT and end in Maine at 3:35 pm EDT.

日全食的路径将在地球表面快速穿越大约115英里宽，将穿过墨西哥的四个州（锡那罗亚州、纳亚里特州、杜兰戈州和科阿韦拉州）、美国的15个州（德克萨斯州、俄克拉荷马州、阿肯色州、密苏里州、伊利诺伊州、肯塔基州、田纳西州、密歇根州、印第安纳州、俄亥俄州、宾夕法尼亚州、纽约州、佛蒙特州、新罕布什尔州和缅因州）以及加拿大的七个省（安大略省、魁北克省、新不伦瑞克省、爱德华王子岛省、新斯科舍省和新不伦瑞克省）。在美国，日全食将于下午1:27 CDT在德克萨斯州开始，并于下午3:35 EDT在缅因州结束。

Related: Where will the April 2024 total solar eclipse be visible from?

相关：2024年4月日全食在在哪里可见？

The path of totality touches a small corner of Tennessee and Michigan. In Tennessee, only the northwest corner is in the path, with a maximum of 2 minutes and 7 seconds at Kentucky Bend/New Madrid Bend. In Michigan, only the southeast corner is in the path, with 1 minute 20 seconds at the exclave of Lost Peninsula Marina.

日全食的路径将触及田纳西州和密歇根州的一个小角落。在田纳西州，只有西北角位于路径上，肯塔基弯/新马德里弯处最长可见2分7秒。在密歇根州，只有东南角位于路径上，失落半岛码头飞地可见1分20秒。

Within any path of totality is a center point, a point of maximum eclipse, where a total solar eclipse will be experienced around midday with the sun and moon at their highest in the sky. It's here where the geometry of the sun, moon, and Earth line up precisely, meaning the slowest-moving shadow — and so the longest totality.

在任何日全食路径中都有一个中心点，即最大日食点，在这里，日全食将在中午左右发生，太阳和月球在天空中的位置最高。正是在这里，太阳、月球和地球的几何位置精确对齐，意味着移动最慢的阴影——因此日全食的时间最长。

On April 8, that point is just 4 miles (6 kilometers) to the north of Nazas, population 3,600, in the Mexican state of Durango. From here, totality will last 4 minutes and 28 seconds.

4月8日，这个点距离墨西哥杜兰戈州的纳萨斯市北部仅4英里（6公里），纳萨斯市人口为3,600。从这个地点，日全食将持续4分28秒。

Solar eclipses come in families called Saros (Greek for repetition). Every 6,585.3 days, a shadow of the moon hits Earth of roughly the same proportions as the previous one. The only reason it doesn't occur in the same place is that .3 of a day (around 8 hours), which means Earth has rotated slightly.

日食以家族的形式出现，称为沙罗周期（希腊语中意为重复）。每6,585.3天，月球的阴影就会以大致相同的比例再次击中地球。它之所以不会在相同的地方发生，是因为有0.3天的偏差（大约8小时），这意味着地球已经稍微旋转了一点。

The total solar eclipse on April 8 is part of Saros 139, which 6,585.3 days previously, on March 29, 2006, produced an almost identical totality for Africa and Asia. The next eclipse in Saros 139 after 2024 will occur on April 20, 2042, when totality is visible from Indonesia, Eastern Malaysia, Brunei and the Philippines.

4月8日的日全食属于沙罗周期139，它在6,585.3天前的2006年3月29日为非洲和亚洲带来了几乎相同的日全食。2024年之后的下一个沙罗周期139的日食将在2042年4月20日发生，届时日全食将可见于印度尼西亚、东马来西亚、文莱和菲律宾。

However, every fourth repetition (54 years), a total solar eclipse occurs in roughly the same place, something called an exeligmos:

然而，每四次重复（54年）中，日全食就会在大致相同的地点发生，这种现象称为“exeligmos”：

March 7, 1970: Mexico, the U.S. (Florida, Georgia, South Carolina, North Carolina, Massachusetts) and Canada (Nova Scotia and Newfoundland)

1970年3月7日：墨西哥、美国（佛罗里达州、乔治亚州、南卡罗来纳州、北卡罗来纳州、马萨诸塞州）和加拿大（新斯科舍省和新不伦瑞克省）。

May 11, 2078: Mexico, the U.S. (Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, North Carolina and Virginia)

2078年5月11日：墨西哥、美国（路易斯安那州、密西西比州、亚拉巴马州、佛罗里达州、乔治亚州、南卡罗来纳州、北卡罗来纳州和弗吉尼亚州）。

Look at the central paths of the two solar eclipses that will strike North America within six months — the annular solar eclipse on October 14, 2023, and the total solar eclipse on April 8, 2024.

看看将在六个月内两次袭击北美的日食的中心路径——2023年10月14日的环形日食和2024年4月8日的日全食。

One shadow moves northwest-southeast, and the other moves southwest-northeast, but why? Though the position and distance of the moon have a huge effect on the eclipse, the differing orientation of the paths is down to Earth's titled axis, which is leaning different ways during both eclipses. In October (fall), the Earth moves downwards as it rotates, while in April (spring), it moves upwards.

一个阴影向西北-东南移动，另一个向西南-东北移动，但为什么会这样？尽管月球的位置和距离对日食有巨大影响，但路径方向的不同是由于地球的倾斜轴在两次日食期间倾斜的方向不同。在10月（秋季），地球在旋转时向下移动，而在4月（春季），它向上移动。

About 40 million people live within the path of totality on April 8, around three-quarters of them in the U.S. Major cities inside the path include Mazatlan and Torreon in Mexico, San Antonio, Austin, Dallas-Fort Worth, Indianapolis, Little Rock, Cleveland, Buffalo and Rochester in the U.S. and Hamilton and Montreal in Canada. That accounts for about 10 million people. However, there are also many huge cities close to the path of totality, whose residents only have to drive very short distances to experience totality — something eclipse-chasers travel worldwide to experience. St Louis, Cincinnati, Toronto and Quebec are very close to the path, while the inhabitants of Houston, Chicago, Detroit, Boston, New York, Philadelphia, Baltimore, and Washington, D.C., are all within 200 miles of the path of totality.

大约4000万人居住在4月8日日全食的路径上，其中约四分之三在美国。路径内的主要城市包括墨西哥的马萨特兰和托雷翁，美国的圣安东尼奥、奥斯汀、达拉斯-沃斯堡、印第安纳波利斯、小石城、克利夫兰、布法罗和罗切斯特，以及加拿大的汉密尔顿和蒙特利尔。这大约占了1000万人。然而，还有许多大城市紧邻日全食的路径，居民只需开车很短的距离就能体验日全食——这是追日食者环游世界所追求的体验。圣路易斯、辛辛那提、多伦多和魁北克都非常接近日全食的路径，而休斯顿、芝加哥、底特律、波士顿、纽约、费城、巴尔的摩和华盛顿特区的居民都在日全食路径200英里范围内。

Neither of the two non-contiguous U.S. states will see a total solar eclipse on April 8. Hawaii will see a 20% partial solar eclipse at sunrise. In comparison, only southeast Alaska west of Juneau — including Glacier Bay National Park and Preserve — will see up to a 5% partial solar eclipse mid-morning. However, Alaska will only have to wait until just after sunrise on March 30, 2033 — almost exactly 10 years later — before it sees a total solar eclipse. A maximum of 2 minutes and 37 seconds of totality will be experienced, with key observing locations within a 500-mile wide path of totality, including Utqiaġvik, Kotzebue, Nome and St Lawrence Island.

4月8日，美国的两个非连续州都不会看到日全食。夏威夷将在日出时看到20%的偏食。相比之下，只有朱诺以西的东南阿拉斯加——包括冰川湾国家公园和保护区——将在上午看到最多5%的偏食。然而，阿拉斯加只需等到几乎正好10年后的2033年3月30日日出后不久，就能看到日全食。最长可达2分37秒的日全食将在宽达500英里的日全食路径上的关键观测地点体验到，包括乌特奇亚维克、科兹布、诺姆和圣劳伦斯岛。

Few will notice it, but this total solar eclipse for North America ceases to exist on the west coast of the U.K. A sunset commences on April 8, from the west coast of Wales, England, and Scotland, where it will be possible to see a tiny bite taken from the sun in the slightest of partial solar eclipses. A very low view of the horizon will be required — in practice, an ocean horizon — as well as clear skies.

很少有人会注意到，但这次北美洲的日全食在英国西海岸将不复存在。4月8日，从威尔士、英格兰和苏格兰的西海岸开始的日落时，人们有可能看到太阳被轻微地咬掉了一小口，这是最轻微的偏食。这需要非常低的地平线视角——实际上，需要一个海洋地平线——以及晴朗的天空。