Moons “Dance” Around Pluto

In a very touching gesture， the New Horizons probe is carrying the ashes of Plutos discoverer， American astronomer Clyde Tombaugh注3. In the canister[小罐] with the ashes is an inscription[題詞] from Alan Stern， the head of the New Horizons mission： “Interned[被拘禁的] herein[于此] are remains of American Clyde W. Tombaugh， discoverer of Pluto and the solar systems ‘third zone. Adelle and Murons boy， Patricias husband， Annette and Aldens father， astronomer， teacher， punster， and friend： Clyde W. Tombaugh （1906-1997）.”

Tombaugh will continue his trip aboard New Horizons， crossing into a new frontier of the solar system beyond Pluto， carrying humanitys hopes and aspirations with him.

Theres a chaotic[混亂的] dance going on at the far end of our solar system. It involves Pluto and five of its closest friends， a study finds.

Hubble Space Telescope images[圖像] of Pluto， its largest moon Charon and tinier moons Styx， Nix， Hydra and Kerberos注1 show the odd movements of these six distant objects. Its like a dance. But it is unlike anything in our solar system to date[迄今為止].

What makes it so odd is that therere two sets of dances going on. First， Pluto and Charon are locked together in their own waltz. It is “as if they are a dumbbell[啞鈴]” with a rod connecting them， this according to study author Mark Showalter of the SETI注2 Institute in California. Its the solar systems only binary[具有兩個(gè)的] planet system.

“Its pretty darn[=damn] weird，” Showalter said.

But Pluto and Charon arent alone. And thats where it gets more complicated.

The four little moons circle the Pluto-Charon combo[聯(lián)合體]. They wobble[搖擺] a bit when they go closer to either Pluto or Charon. They are being pushed and pulled by the two bigger objects.

Those four moons orbit[繞……軌道而行] Pluto-Charon in a precise rhythmic[有節(jié)奏的] way. But there is a twist[扭轉(zhuǎn)]. They also interact[互相作用] when they near each other. So it seems like they all dance to one overall beat， but not quite in the same way. They are just doing their own thing， said planetary[行星的] scientist Heidi Hammel of the Association of Universities for Research in Astronomy.

“Its kind of like youd see at a Grateful Dead注3 concert，” Hammel said. She wasnt part of the study， but she praised it as giving us a glimpse of what might be happening in other distant star systems， where there are two stars and planets that revolve around them. It is like the mythical[虛構(gòu)的] Star Wars world of Tatooine注4.

With the tiny moons wobbling and flipping over[翻過(guò)來(lái)] in an unpredictable[不可預(yù)知的] and chaotic way， if you lived on Nix or Hydra， the sun would come up in different parts of the sky， if at all on some days， Showalter said.

“Its a very strange world，” he said. “You would literally not know if the sun is coming up tomorrow.”

新地平線號(hào)上載著冥王星的發(fā)現(xiàn)者、美國(guó)天文學(xué)家克萊德·湯博的骨灰，這一舉動(dòng)非常令人感動(dòng)。裝著骨灰的小罐上刻著新地平線號(hào)任務(wù)的領(lǐng)導(dǎo)人艾倫·斯特恩的題詞：“這里埋葬著冥王星和太陽(yáng)系‘第三區(qū)的發(fā)現(xiàn)者、阿黛爾和穆倫的兒子、帕特麗夏的丈夫、安妮特和奧爾登的父親、美國(guó)天文學(xué)家、教師、風(fēng)趣的朋友：克萊德·W·湯博（1906—1997）。”

湯博將會(huì)在新地平線號(hào)上繼續(xù)他的旅程，越過(guò)冥王星，穿至太陽(yáng)系的新邊界，人類的希望和抱負(fù)與之同在。

在我們太陽(yáng)系遙遠(yuǎn)的盡頭正舉行著一場(chǎng)混亂的舞會(huì)。一項(xiàng)研究發(fā)現(xiàn)，舞者包括了冥王星和它最親近的五個(gè)朋友。

哈勃空間望遠(yuǎn)鏡觀測(cè)到的圖像顯示了冥王星、它最大的衛(wèi)星卡戎（冥衛(wèi)一）和其他較小的衛(wèi)星斯提克斯（冥衛(wèi)五）、尼克斯（冥衛(wèi)二）、許德拉（冥衛(wèi)三）及科波若斯（冥衛(wèi)四）這六個(gè)遙遠(yuǎn)星體所發(fā)生的異動(dòng)。那就像是一場(chǎng)舞會(huì)，但又和我們太陽(yáng)系迄今為止的一切活動(dòng)都有所不同。

它如此非同尋常，是因?yàn)橛袃商孜璧冈谕瑫r(shí)進(jìn)行。首先，冥王星和卡戎被鎖在了它們自己的華爾茲舞步中。據(jù)加州地外文明探索學(xué)會(huì)的研究作者馬克·肖華特所說(shuō)，它們“就像是個(gè)啞鈴”由一根短柄相連在一起。這是太陽(yáng)系里唯一的一個(gè)雙星系統(tǒng)。

“這真的是太奇怪了，”肖華特說(shuō)。

但冥王星和卡戎并非唯一奇異的現(xiàn)象，接下來(lái)的就更復(fù)雜了。

這四個(gè)小衛(wèi)星圍繞著冥王星——卡戎組合旋轉(zhuǎn)。當(dāng)它們靠近冥王星或卡戎時(shí)便會(huì)有點(diǎn)搖晃。它們正被這兩個(gè)更大的物體推遠(yuǎn)或拉近 。

這四個(gè)衛(wèi)星以一種精確的步調(diào)環(huán)繞著冥王星——卡戎組合運(yùn)行，但有時(shí)也會(huì)有一個(gè)翻滾。當(dāng)它們彼此靠近時(shí)也會(huì)互相影響。所以看上去它們似乎都沿著同一個(gè)節(jié)奏舞蹈，卻又不盡然。它們不過(guò)是在忙著自己的事情，天文研究大學(xué)協(xié)會(huì)的行星科學(xué)家海蒂·哈默爾如是說(shuō)。

“這就像是你在一場(chǎng)感恩而死樂(lè)隊(duì)的演唱會(huì)上會(huì)看到的情形，”哈默爾說(shuō)。她并未參與這個(gè)研究，但她對(duì)其稱贊有加，認(rèn)為這讓我們瞥見了其他遙遠(yuǎn)的恒星系統(tǒng)可能會(huì)發(fā)生的情景。在那里有兩個(gè)恒星及環(huán)繞其外的行星，就像是虛構(gòu)的《星球大戰(zhàn)》世界里的行星塔圖因。

“隨著這些小衛(wèi)星以一種無(wú)法預(yù)測(cè)且混亂的方式搖晃和突然翻轉(zhuǎn)，如果你居住在尼克斯或者許德拉上，太陽(yáng)會(huì)從天空的不同方位升起，如果在某些日子它確實(shí)會(huì)升起的話?！毙とA特說(shuō)。

“那是一個(gè)非常奇怪的世界，”他說(shuō)?！澳阏娴牟恢烂魈斓奶?yáng)是否會(huì)升起。”

注1：冥王星外的五顆矮行星：冥衛(wèi)一卡戎（Charon）、冥衛(wèi)五斯提克斯（Styx）、冥衛(wèi)二尼克斯（Nix）、冥衛(wèi)三許德拉（Hydra）以及冥衛(wèi)四科波若斯（Kerberos）。

注2：SETI是一項(xiàng)利用全球聯(lián)網(wǎng)的計(jì)算機(jī)共同搜尋地外文明的科學(xué)實(shí)驗(yàn)計(jì)劃。

注3：感恩而死樂(lè)隊(duì)是于1964年組建的美國(guó)樂(lè)隊(duì)，風(fēng)格常在迷幻搖滾和鄉(xiāng)村搖滾之間自由切換，1995年解散。

注4：塔圖因（Tatooine），又譯塔圖音，是《星球大戰(zhàn)》中圍繞著一個(gè)雙星系統(tǒng)運(yùn)動(dòng)的行星。