飛向月球背面：九個問題，快速了解嫦娥四號
中國的目標(biāo)是去一個沒有人去過的地方：月球背面。
A rocket carrying the Chang’e-4 lunar lander blasted off at about 2:23 a.m. local time on Saturday from Xichang Satellite Launch Center in southern China. (In the United States, it was still midday Friday). Chinese authorities did not broadcast the launch, but an unofficial live stream recorded near the site showed the rocket rise from the launchpad until its flames looked like a bright star in the area’s dark skies.
搭載著嫦娥四號登月飛行器的火箭于當(dāng)?shù)貢r間周六凌晨2點23分(在美國還是周五中午時分)從中國南部的西昌衛(wèi)星發(fā)射中心升空。中國當(dāng)局沒有播出這次發(fā)射，但是在該站點附近錄制的非官方直播節(jié)目顯示火箭從發(fā)射臺升起，直到它的火焰變得仿佛夜空里的一顆明星。
Nearly one hour later, Xinhua, China’s state-run news agency reported that Chang’e-4 had successfully launched.
近一個小時后，中國官方通訊社新華社報道嫦娥四號已成功發(fā)射。
Exactly when it will set down at its destination has not yet been announced — possibly in early January — but Chang’e-4 will provide the first close-up look at a part of the moon that is eternally out of view from Earth.
目前為止，還沒有宣布嫦娥四號究竟何時將在目的地著陸——可能是在1月初——但嫦娥4號將首次近距離觀察從地球視角內(nèi)永遠(yuǎn)看不到的那部分月球。
What is Chang’e-4?
嫦娥四號是什么?
Chang’e-4 includes two main parts: the main lander weighing about 2,400 pounds and a 300-pound rover. By comparison, NASA’s Opportunity rover on Mars weighs about 400 pounds, and the Curiosity rover there is much bigger, at 2,000 pounds.
嫦娥四號主要包括兩個部分：重約2400磅的主著陸器和一個300磅的月球探測車。相比之下美國宇航局(NASA)的機(jī)遇號火星探測車重約400磅，而同在火星的好奇號探測車要大的多，重達(dá)2000磅。
The spacecraft is largely a clone of Chang’e-3, which landed on the moon in 2013. Indeed, Chang’e-4 was built as the backup in case the first attempt failed. With the success — the first soft landing of any spacecraft on the moon since 1976 — the Chinese outfitted Chang’e-4 with a different set of instruments and decided to send it to a different location.
該航天器很大程度上是嫦娥三號的復(fù)制品，后者于2013年降落在月球上。事實上，嫦娥四號是作為備份制造的，以防止第一次嘗試失敗。隨著嫦娥三號的成功——這是自1976年以來首次有航天器在月球上軟著陸——中國人給嫦娥四號配置了不同的儀器，并決定將它送到不同的地點。
Where is Chang’e-4 going? 嫦娥四號要去哪里?
The rover will land in the 110-mile-wide Von Kármán crater. It is on the far side of the moon, which is always facing away from Earth. (The moon is what planetary scientists call “tidally locked” to the rotation of the Earth. That is, its period of rotation — its day — is the same as the time it takes to make one orbit around Earth.)
月球車將在110英里寬的馮·卡門(VonKármán)撞擊坑著陸。它位于永遠(yuǎn)背離地球的月球背面。(按行星科學(xué)家的說法，月亮繞地球的旋轉(zhuǎn)是“潮汐鎖定”的。也就是說，它自身的旋轉(zhuǎn)周期——它的一天——與圍繞地球軌道一周所需的時間相同。
The crater is within an area known as the South Pole-Aitken basin, a gigantic, 1,600-mile-wide crater at the bottom of the moon, which has a mineralogy distinct from other locations. That may reflect materials from the inside of the moon that were brought up by the impact that created the basin.
撞擊坑位于被稱為南極-艾特肯盆地(Aitken basin)的區(qū)域內(nèi)，這是一個位于月球底部的巨大撞擊坑，寬1600英里，其礦物質(zhì)與其他地方不同。這可能反映了月球內(nèi)部受盆地形成的影響而產(chǎn)生的物質(zhì)。
The far side is also considerably more mountainous than the near side for reasons not yet understood.
由于一些尚未被理解的原因，月球背面也比正面多了相當(dāng)多的山。
What will Chang’e-4 study? 嫦娥四號將研究什么?
The suite of instruments on the rover and the lander include cameras, ground-penetrating radar and spectrometers to help identify the composition of rocks and dirt in the area. And China’s space agency has collaborated with other countries. One instrument was developed at Kiel University in Germany; another was provided by the Swedish Institute of Space Physics.
月球車和著陸器上的配套設(shè)備，包括攝像機(jī)、探地雷達(dá)和光譜儀，將有助于識別該區(qū)域的巖石和泥土的成分。中國航天局與其他國家進(jìn)行了合作。其中一個儀器由德國基爾大學(xué)(Kiel University)開發(fā);還有一個由瑞典空間物理研究所(Swedish Institute of Space Physics)提供。
The instruments will probe the structure of the rocks beneath the spacecraft and study the effects of the solar wind striking the lunar surface. Chang’e-4 will also test the ability of making radio astronomy observations from the far side of the moon, without the effects of noise and interference from Earth.
這些儀器將探測航天器下方巖石的結(jié)構(gòu)，并研究太陽風(fēng)撞擊月球表面產(chǎn)生的影響。在不受地球噪聲和干擾影響的情況下，嫦娥四號還將測試從月球背面進(jìn)行射電天文觀測的能力。
According to the Xinhua news agency, Chang’e-4 is also carrying an intriguing biology experiment to see if plant seeds will germinate and silkworm eggs will hatch in the moon’s low gravity.
據(jù)新華社報道，嫦娥四號還將進(jìn)行一項有趣的生物學(xué)實驗，看看在月球的低重力環(huán)境下，植物種子是否會發(fā)芽，蠶卵是否會孵化。
How will the spacecraft communicate with Earth?
航天器如何與地球溝通?
Because the moon blocks radio signals from our planet, the Chinese launched a satellite, called Queqiao, in May. It is circling high over the far side of the moon, and will relay messages between Earth and the Chang’e-4 lander.
由于月球擋住了地球發(fā)出的無線電波信號，中國于今年5月發(fā)射了“鵲橋”衛(wèi)星。該衛(wèi)星沿月球較遠(yuǎn)一側(cè)的高空環(huán)繞運行，將承擔(dān)地球與嫦娥四號著陸器之間的通信任務(wù)。
When will Chang’e-4 land on the moon?
嫦娥四號將于什么時候在月球著陸?
China’s space agency has not announced a landing date, though some expect that will be the first week of January, when the sun will be shining over the far side of the moon, an important consideration because Chang’e-4 is solar-powered.
中國航天局尚未公布著陸日期，但有預(yù)計稱將在1月的第一周，屆時太陽將照在月球較遠(yuǎn)一側(cè)，嫦娥四號為太陽能驅(qū)動，這一考量很重要。
Zhang Xiaoping, an associate professor from Space Science Institute/Lunar and Planetary Science Laboratory of Macau University of Science and Technology, said that the spacecraft would follow the Chang’e-3’s trajectory. That means it would arrive in three to five days and then orbit the moon for several days (13 in the case of Chang’e-3) while preparing for the landing, he said.
中國國際空間科學(xué)研究所/澳門科技大學(xué)月球與行星科學(xué)實驗室助理教授張小平表示，航天器將依照嫦娥三號的路線行進(jìn)。這意味著它將于三至五日到達(dá)，然后繞月球軌道運行數(shù)日(嫦娥三號當(dāng)時運行了13天)，同時做好著陸準(zhǔn)備。
Wait, I thought the far side of the moon was dark.
等等，我以為月球遠(yuǎn)側(cè)是黑的。
The far side is not dark all of the time.
較遠(yuǎn)一側(cè)并非總是一片漆黑。
The first new moon of 2019 is Jan. 6. That’s when you cannot see the moon because the dark side — the side that is in shadow facing away from the sun — is facing Earth. And when the near side of the moon is dark, the far side is awash in bright sunshine.
2019年的第一輪新月在1月6日。那時候你看不見月亮，因為黑的一面，即處于背對太陽的陰影之中的那一面，正對著地球。當(dāng)月球較近的一側(cè)變黑，較遠(yuǎn)一側(cè)則沐浴在明亮的陽光下。
Why is China so secretive about all of this?
為什么中國對這些這么保密?
Chinese officials have talked about Chang’e-4 in public, but their interactions with journalists more resemble the carefully managed strategy used by the Soviet program during the Cold War rather than the more open publicity by NASA and many other space agencies. That way, the Chinese, like the Soviets, could boast about the successes and downplay any failures.
中國的官員曾公開談?wù)撨^嫦娥四號，但他們與記者的互動更像是冷戰(zhàn)時期蘇聯(lián)項目中所用的細(xì)心安排的策略，而非像美國國家航空航天局(NASA)及許多其它航天機(jī)構(gòu)那種公開宣傳的方式。這樣一來，中國就和蘇聯(lián)一樣，可以夸耀成功，如有失敗又可以淡化。
What does Chang’e mean?
嫦娥是什么意思?
In Chinese mythology, Chang’e is the goddess of the moon. Other missions have been named after her, too.
在中國神話里，嫦娥是月亮女神。其它行動也有以嫦娥命名的。
Chang’e-1 and 2 went into orbit around the moon but did not land. Chang’e-1 was launched in 2007. Chang’e-2 followed in 2010.
嫦娥一號和二號曾進(jìn)入軌道繞月運行，但未著陸。嫦娥一號于2007年發(fā)射。嫦娥二號隨后于2010年發(fā)射。
The next step in China’s moon program is for the Chang’e-5 robotic spacecraft to land on the moon and then bring rock samples back to Earth for additional study.
中國月球計劃的下一步是讓嫦娥五號非載人航天器登月，將巖石樣本帶回地球進(jìn)行進(jìn)一步的研究。
Chang’e-5 was supposed to head to the moon before Chang’e-4, but a launch failure of the large Chinese rocket needed to carry it to space delayed the mission until at least 2019.
嫦娥五號本應(yīng)在嫦娥四號之前奔月，但由于運載它到太空的大型中國火箭發(fā)射失敗，其行程被推至2019年以后。
Who else is planning to go to the moon?
還有哪些國家有登月計劃?
Next year, the Indian government is planning to launch a mission, Chandrayaan-2, that includes an orbiter, a lander and a rover. SpaceIL, an Israeli team that was a finalist in the Google Lunar X Prize, is also still aiming to send a robotic lander to the moon early next year, even though the $20 million prize has expired.
印度政府計劃于明年進(jìn)行名為“月船二號”(Chandrayaan-2)的任務(wù)，其中包括了軌道器、著陸器和探測器。入圍谷歌“月球X獎”的以色列公司SpaceL也仍在準(zhǔn)備于明年初發(fā)射非載人著陸器到月球，雖然2000萬美元獎金已過期。
NASA announced last week that nine companies will compete for robotic missions to carry science experiments to the moon. The space agency said the first of those could go as early as 2019, but most of the companies said they would not be ready until 2021.
上周，美國國家航空航天局宣布，九家公司將競爭運載科學(xué)實驗到月球的非載人行動。該航天局表示，其中的首批行動可能在2019年就會開始，但大多數(shù)公司稱他們要到2021年才能準(zhǔn)備到位。
Jim Bridenstine, the NASA administrator, has praised the Chang’e-4 mission as exciting, and at the International Astronautical Congress in Bremen, Germany in October, talked of possible collaboration with the Chinese space agency. Federal laws limit any NASA interaction with the Chinese.
美國國家航空航天局局長吉姆· 布里登斯廷(Jim Bridenstine)稱贊嫦娥四號是一項激動人心的任務(wù)，并曾于十月份在德國不來梅港市舉行的國際宇航大會上談到與中國的航天局合作的可能。聯(lián)邦法律禁止美國國家航空航天局與中國進(jìn)行任何互動。vg
