這是已知的第一顆來自太陽(yáng)系外的彗星

這是已知的第一顆來自太陽(yáng)系外的彗星

Our solar system is getting another visitor from a faraway galaxy.

我們的太陽(yáng)系迎來了另一位來自遙遠(yuǎn)星系的訪客。

C/2019 Q4 hasn't officially been designated a comet yet, but it bears an uncanny resemblance to one. (Photo: Gemini Observatory/NSF/AURA)

An amateur astronomer from Crimea named Gennady Borisov first spotted the fast-moving fleck in the night sky last month. Since then, both Hawaii's Gemini Observatory and Spain's William Herschel Telescope confirmed a trajectory that could take it within 190 million miles of our sun.

一位來自克里米亞的業(yè)余天文學(xué)家Gennady Borisov上個(gè)月首次在夜空中發(fā)現(xiàn)了這個(gè)快速移動(dòng)的斑點(diǎn)。從那以后，夏威夷的雙子座天文臺(tái)和西班牙的威廉·赫歇爾望遠(yuǎn)鏡都證實(shí)了這條軌道可以把它帶到離太陽(yáng)1.9億英里以內(nèi)的地方。

The Gemini Observatory even managed to snap a startling full-color picture of the celestial body as it streaked through the heavens.

雙子座天文臺(tái)甚至成功地拍下了一幅令人吃驚的天體在天空中劃過時(shí)的全彩照片。

And, judging by its woolly white halo and telltale tail, it looks like we're going to be entertaining our first interstellar comet.

而且，從它毛茸茸的白色光暈和能說明問題的尾巴判斷，它看起來像是要招待我們的第一顆星際彗星。

Publishing their findings this month in the journal ArXiv, the Polish researchers who analyzed the data have dubbed the visitor C/2019 Q4 (Borisov).

本月，波蘭研究人員在《ArXiv》雜志上發(fā)表了他們的研究成果，他們分析了這些數(shù)據(jù)，并將其命名為游客C/2019 Q4 (Borisov)。

"Both orbital and morphological properties of this body show that this is the first certain case of an interstellar comet," the authors note in the study, which has yet to be reviewed by peers.

“這顆天體的軌道和形態(tài)特征都表明，這是第一顆星際彗星，”作者在研究中指出，這項(xiàng)研究尚未得到同行的評(píng)論。

This would mark the first time we've detected an interstellar comet. The ones that typically blaze through our neighborhood hail from within the solar system — either from that icy outermost region known as the Oort Cloud or the Kuiper Belt, a veritable comet factory just beyond Neptune's orbit.

這將是我們首次探測(cè)到星際彗星。那些通常在我們周圍燃燒的彗星來自太陽(yáng)系內(nèi)部——要么來自被稱為奧爾特云(Oort Cloud)的最外層結(jié)冰區(qū)域，要么來自柯伊伯帶(Kuiper Belt)，這是海王星軌道之外一個(gè)名副其實(shí)的彗星工廠。

And while some of these celestial objects don't come around here very often — Comet West, for example, has an orbital period of about 250,000 years — they all call our solar neighborhood home. In all, there are likely more than 6,000 comets sailing around our space, all eventually brought to heel by our sun's gravitational leash.

雖然這些天體中有一些并不經(jīng)常出現(xiàn)在這里——例如，慧星韋斯特的軌道周期約為25萬年——但它們都把我們的太陽(yáng)鄰居稱為家。總之，可能有超過6000顆彗星在我們的太空中航行，最終都被太陽(yáng)的引力牽引著。

But C/2019 Q4 has likely made the longest journey of all. Researchers say it won't loop around our sun, like its domestic counterparts. It's also traveling at a torrid 93,000 miles per hour — a speed that's far faster than any of the local spaceballs could muster. At that pace, not even the sun will be able to reel it in.

但C/2019年第四季度可能是所有旅行中最長(zhǎng)的。研究人員表示，它不會(huì)像國(guó)內(nèi)的太陽(yáng)那樣環(huán)繞太陽(yáng)運(yùn)行。它還以每小時(shí)93000英里的驚人速度飛行——這一速度遠(yuǎn)遠(yuǎn)超過了當(dāng)?shù)厝魏我粋€(gè)太空球的速度。以這樣的速度，連太陽(yáng)都無法把它卷進(jìn)去。

"After getting enough data, I suspect we'll be assigning a permanent designation to say this object is interstellar," NASA astronomer Davide Farnocchia tells The Verge. "But basically, there's no doubt from the trajectory that it is interstellar."

NASA天文學(xué)家Davide Farnocchia告訴The Verge網(wǎng)站說:“在獲得足夠的數(shù)據(jù)后，我懷疑我們會(huì)給這個(gè)天體賦予一個(gè)永久性的稱號(hào)，說它是星際的。”“但從軌道上看，它是星際的，這是毫無疑問的。”

Artist's impression of the first known interstellar asteroid, 'Oumuamua. (Photo: M. Kornmesser/ESO)

Strangely enough, this is the second time we've had an interstellar visitor in as many years. In 2017, a very strange object known as 'Oumuamua graced our solar system. Its unwieldy, cigar-like dimensions, unknown origin point and blazing speed sparked a frenzy of scientific speculation. While some scientists suggested it's a hobbled, tail-less comet that has been wandering the galaxy for billions of years, others just came right out and said what many of us were thinking: alien spaceship.

奇怪的是，這是這么多年來我們第二次迎來星際訪客。2017年，一個(gè)名為“Oumuamua”的非常奇怪的天體出現(xiàn)在我們的太陽(yáng)系中。它笨重的雪茄狀外形、未知的起源點(diǎn)和驚人的速度引發(fā)了一場(chǎng)瘋狂的科學(xué)猜測(cè)。雖然一些科學(xué)家認(rèn)為這是一顆步履蹣跚、沒有尾巴的彗星，已經(jīng)在銀河系中游蕩了數(shù)十億年，但另一些科學(xué)家卻直截了當(dāng)?shù)卣f出了我們?cè)S多人的想法:外星人的宇宙飛船。

C/2019 Q4 is a little less ambiguous. Even though it was born in an incomprehensibly foreign space, it bears all the telltale trappings of comethood — specifically a lustrous tail of glitter likely caused by outgassing from its ice-cold heart.

C/2019年第4季度沒有那么模糊。盡管它出生在一個(gè)難以理解的陌生空間，但它身上卻有著所有能說明問題的喜劇特征——特別是一條閃閃發(fā)亮的尾巴，很可能是由它冰冷的心臟釋放出的氣體造成的。

In any case, we'll get a chance to scrutinize C/2019 Q4 a lot more closely as it brightens our doorstep over the coming weeks. While 'Oumuamua didn't stick around long enough for us to unfurl the "Welcome to Earth" banner, C/2019 Q4 should make its nearest pass to Earth in December. It won't be quite as intimate as 'Oumuamua's visit, which scraped within 180 million miles of Earth. But it will light up the night sky a lot longer. C/2019 Q4's flyby will peak at the end of the year, but will be present through April, when it finally bids our solar system a fond farewell.

無論如何，我們將有機(jī)會(huì)更仔細(xì)地審視C/2019第四季度，因?yàn)樗鼘⒃谖磥韼字苷樟廖覀兊拇箝T。雖然“Oumuamua沒有停留足夠長(zhǎng)的時(shí)間讓我們展開“歡迎來到地球”的橫幅，但C/2019年第4季度應(yīng)該在12月到達(dá)地球。這次訪問不會(huì)像“Oumuamua的訪問”那么親密，“Oumuamua的訪問”距離地球不到1.8億英里。但它將照亮夜空更長(zhǎng)的時(shí)間。C/2019年第四季度的凌空飛行將在今年年底達(dá)到頂峰，但將持續(xù)到4月，屆時(shí)它將與我們的太陽(yáng)系告別。

And reports back to the mothership.

并向母艦報(bào)告。