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豐富的“流星”而聞名，預(yù)計(jì)2019年的流星雨將會(huì)稍微平靜一些。

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.

與去年每小時(shí)80顆流星不同的是，今年的流星雨將沒(méi)有去年那么耀眼。英仙座流星雨的高峰將出現(xiàn)在8月12日晚上，屆時(shí)天文觀測(cè)者每小時(shí)只能看到15到20顆流星。據(jù)《國(guó)家地理》報(bào)道，由于滿月離英仙座流星雨的頂峰只有幾天的距離，由于明亮的月亮發(fā)出的光，要想看到流星雨將非常困難。

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.

這場(chǎng)流星雨正式開始于7月17日——地球首次遇到109P/Swift-Tuttle彗星留下的粒子——并將持續(xù)到8月24日。這顆彗星于1862年被發(fā)現(xiàn)，但隨后的流星雨已經(jīng)被觀測(cè)了2000年。陣雨有時(shí)每小時(shí)能產(chǎn)生200顆流星。

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.

當(dāng)彗星進(jìn)入太陽(yáng)系內(nèi)部時(shí)，它們會(huì)留下粒子(巖石、塵埃和其他各種各樣的碎片)，當(dāng)這些粒子撞擊地球的大氣層時(shí)，它們會(huì)升溫——有時(shí)伴隨著明亮的光爆發(fā)。這些倒霉的粒子在蒸發(fā)前以每小時(shí)10萬(wàn)英里的速度運(yùn)動(dòng)。流星的大小從沙粒到大理石不等。如果你足夠幸運(yùn)，在這個(gè)過(guò)程中看到了其中一個(gè)注定要?dú)绲牧Ｗ?，那么你已?jīng)看到了一顆流星。如果碎片沒(méi)有燃燒起來(lái)，撞到表面，你就得到了一塊隕石。

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

在流星雨期間看到流星的幾率最大，因?yàn)槲覀冎罆?huì)發(fā)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.

為了獲得最大的體驗(yàn)，最好找一個(gè)遠(yuǎn)離城市人造燈光的地方。流星雨可以用肉眼看到;不需要花哨的設(shè)備。夜貓子們會(huì)很高興地知道，黎明前(午夜后)是最佳觀賞時(shí)間。需要注意的是，今年月球的亮度將達(dá)到80%，這可能會(huì)讓觀測(cè)流星雨變得更加困難。

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.

流星雨是以它們的起源星座命名的。在這種情況下，它是英仙座，位于+90度和-35度之間的緯度，以神話中殺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.

除了這次特別的光秀，還有很多關(guān)于彗星背后的有趣事實(shí)值得我們?nèi)チ私狻Ｋ雇蛱?塔特爾彗星直徑約16英里，大小與導(dǎo)致恐龍滅絕的那顆流星大致相同。上世紀(jì)90年代，人們?cè)鴵?dān)心斯威夫特-塔特爾會(huì)與地球接觸，從而讓我們走上恐龍的道路，但這一理論很快就被揭穿了。

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，據(jù)Space.com報(bào)道，它也是“已知的在地球附近重復(fù)經(jīng)過(guò)”的最大天體。彗星上一次出現(xiàn)在這里是在1992年，直到2126年才會(huì)出現(xiàn)。幸運(yùn)的是，斯威夫特·塔特爾留下了大量的粒子，以英仙座流星雨的形式留給我們欣賞，這證明了一顆彗星的垃圾是天文學(xué)家的財(cái)富。