英仙座流星雨:你需要知道的

英仙座流星雨:你需要知道的

The annual Perseid meteor shower, known for its prolific offering of "shooting stars," is expected to be a bit muted in 2019.

一年一度的英仙座流星雨以其丰富的“流星”而闻名，预计2019年的流星雨将会稍微平静一些。

Unlike last year, when there were as many as 80 meteors per hour, the display will be less brilliant this year. The peak of the Perseid meteor shower will occur on the evening of Aug. 12, when skywatchers should be able to see only about 15 to 20 meteors per hour. With the full moon only a couple of days away from the Perseids' peak, views of the meteors will be difficult because of the bright moon's light, reports National Geographic.

与去年每小时80颗流星不同的是，今年的流星雨将没有去年那么耀眼。英仙座流星雨的高峰将出现在8月12日晚上，届时天文观测者每小时只能看到15到20颗流星。据《国家地理》报道，由于满月离英仙座流星雨的顶峰只有几天的距离，由于明亮的月亮发出的光，要想看到流星雨将非常困难。

Perseid meteors, like this one seen sailing over the Embudo Valley in New Mexico, are the result of chunks of rocks and particles left behind by the Swift-Tuttle comet. (Photo: Mike Lewinski [CC by 2.0]/Flickr)

The shower officially began on July 17 — when Earth first encountered particles left behind from the comet 109P/Swift-Tuttle — and will persist until Aug. 24. The comet was discovered in 1862, but its ensuing meteor showers have been witnessed for 2,000 years. The shower sometimes creates as many as 200 shooting stars per hour.

这场流星雨正式开始于7月17日——地球首次遇到109P/Swift-Tuttle彗星留下的粒子——并将持续到8月24日。这颗彗星于1862年被发现，但随后的流星雨已经被观测了2000年。阵雨有时每小时能产生200颗流星。

When comets enter the inner solar system, they leave behind particles (rock, dust and other assorted debris), and when these particles hit our planet's atmosphere, they heat up — sometimes with brilliant bursts of light. These ill-fated particles travel at 100,000 miles per hour just before they vaporize. The sizes of the meteors range from grains of sand to marbles. If you're lucky enough to catch sight of one of these doomed particles in the act, you've witnessed a shooting star. If the debris doesn't burn up, and it hits the surface, you've got a meteorite.

当彗星进入太阳系内部时，它们会留下粒子(岩石、尘埃和其他各种各样的碎片)，当这些粒子撞击地球的大气层时，它们会升温——有时伴随着明亮的光爆发。这些倒霉的粒子在蒸发前以每小时10万英里的速度运动。流星的大小从沙粒到大理石不等。如果你足够幸运，在这个过程中看到了其中一个注定要毁灭的粒子，那么你已经看到了一颗流星。如果碎片没有燃烧起来，撞到表面，你就得到了一块陨石。

The odds of seeing shooting stars are best during meteor showers, simply because we know what to expect.

在流星雨期间看到流星的几率最大，因为我们知道会发生什么。

To get the most out of the experience, it's best to find a place far away from the artificial light of cities. The shower can be seen by the naked eye; no fancy equipment is required. Night owls will be happy to know that the pre-dawn hours (after midnight) will offer the best viewing time. Be advised that the moon will be pretty bright this year at 80% illuminated, which may make viewing the meteor shower a little more difficult.

为了获得最大的体验，最好找一个远离城市人造灯光的地方。流星雨可以用肉眼看到;不需要花哨的设备。夜猫子们会很高兴地知道，黎明前(午夜后)是最佳观赏时间。需要注意的是，今年月球的亮度将达到80%，这可能会让观测流星雨变得更加困难。

Meteor showers are named after the constellation from which they appear to originate. In this case, it's the constellation Perseus, which is located at latitudes between +90 degrees and -35 degrees and is named after the hero from mythology who killed Medusa.

流星雨是以它们的起源星座命名的。在这种情况下，它是英仙座，位于+90度和-35度之间的纬度，以神话中杀死美杜莎的英雄命名。

Aside from this particular light show, there are plenty of other interesting facts to know about the comet behind it. Comet Swift-Tuttle is about 16 miles across, which is roughly the same size as the meteor that caused the extinction of the dinosaurs. There was a scare in the 1990s that Swift-Tuttle would come into contact with the Earth sending us the way of the dinosaurs, but that theory was quickly debunked.

除了这次特别的光秀，还有很多关于彗星背后的有趣事实值得我们去了解。斯威夫特-塔特尔彗星直径约16英里，大小与导致恐龙灭绝的那颗流星大致相同。上世纪90年代，人们曾担心斯威夫特-塔特尔会与地球接触，从而让我们走上恐龙的道路，但这一理论很快就被揭穿了。

However, according to Space.com, it's also the largest object "known to make repeated passes near Earth." The comet, last here in 1992, isn't due back until 2126. Fortunately, Swift-Tuttle has left plenty of particles in its wake for our enjoyment in the form of the Perseid meteor shower, proving that one comet's trash is an astronomer's treasure.

然而，据Space.com报道，它也是“已知的在地球附近重复经过”的最大天体。彗星上一次出现在这里是在1992年，直到2126年才会出现。幸运的是，斯威夫特·塔特尔留下了大量的粒子，以英仙座流星雨的形式留给我们欣赏，这证明了一颗彗星的垃圾是天文学家的财富。