In 1970, a Zambia-based nun named Sister Mary Jucunda wrote to Dr. Ernst Stuhlinger, then-associate director of science at NASA's Marshall Space Flight Center, in response to his ongoing research into a piloted mission to Mars. Specifically, she asked how he could suggest spending billions of dollars on such a project at a time when so many children were starving on Earth。

Stuhlinger soon sent the following letter of explanation to Sister Jucunda, along with a copy of "Earthrise," the iconic photograph of Earth taken in 1968 by astronaut William Anders, from the Moon (also embedded in the transcript). His thoughtful reply was later published by NASA, and titled, "Why Explore Space?"

(Source: Roger Launius, via Gavin Williams; Photo above: The surface of Mars, taken by Curiosity today, August 6th, 2012. Via NASA。)

May 6, 1970

Dear Sister Mary Jucunda:

Your letter was one of many which are reaching me every day, but it has touched me more deeply than all the others because it came so much from the depths of a searching mind and a compassionate heart. I will try to answer your question as best as I possibly can。

First, however, I would like to express my great admiration for you, and for all your many brave sisters, because you are dedicating your lives to the noblest cause of man: help for his fellowmen who are in need。

You asked in your letter how I could suggest the expenditures of billions of dollars for a voyage to Mars, at a time when many children on this Earth are starving to death. I know that you do not expect an answer such as "Oh, I did not know that there are children dying from hunger, but from now on I will desist from any kind of space research until mankind has solved that problem!" In fact, I have known of famined children long before I knew that a voyage to the planet Mars is technically feasible. However, I believe, like many of my friends, that travelling to the Moon and eventually to Mars and to other planets is a venture which we should undertake now, and I even believe that this project, in the long run, will contribute more to the solution of these grave problems we are facing here on Earth than many other potential projects of help which are debated and discussed year after year, and which are so extremely slow in yielding tangible results。

Before trying to describe in more detail how our space program is contributing to the solution of our Earthly problems, I would like to relate briefly a supposedly true story, which may help support the argument. About 400 years ago, there lived a count in a small town in Germany. He was one of the benign counts, and he gave a large part of his income to the poor in his town. This was much appreciated, because poverty was abundant during medieval times, and there were epidemics of the plague which ravaged the country frequently. One day, the count met a strange man. He had a workbench and little laboratory in his house, and he labored hard during the daytime so that he could afford a few hours every evening to work in his laboratory. He ground small lenses from pieces of glass; he mounted the lenses in tubes, and he used these gadgets to look at very small objects. The count was particularly fascinated by the tiny creatures that could be observed with the strong magnification, and which he had never seen before. He invited the man to move with his laboratory to the castle, to become a member of the count's household, and to devote henceforth all his time to the development and perfection of his optical gadgets as a special employee of the count。

The townspeople, however, became angry when they realized that the count was wasting his money, as they thought, on a stunt without purpose. "We are suffering from this plague," they said, "while he is paying that man for a useless hobby!" But the count remained firm. "I give you as much as I can afford," he said, "but I will also support this man and his work, because I know that someday something will come out of it!"

Indeed, something very good came out of this work, and also out of similar work done by others at other places: the microscope. It is well known that the microscope has contributed more than any other invention to the progress of medicine, and that the elimination of the plague and many other contagious diseases from most parts of the world is largely a result of studies which the microscope made possible。

The count, by retaining some of his spending money for research and discovery, contributed far more to the relief of human suffering than he could have contributed by giving all he could possibly spare to his plague-ridden community。

The situation which we are facing today is similar in many respects. The President of the United States is spending about 200 billion dollars in his yearly budget. This money goes to health, education, welfare, urban renewal, highways, transportation, foreign aid, defense, conservation, science, agriculture and many installations inside and outside the country. About 1.6 percent of this national budget was allocated to space exploration this year. The space program includes Project Apollo, and many other smaller projects in space physics, space astronomy, space biology, planetary projects, Earth resources projects, and space engineering. To make this expenditure for the space program possible, the average American taxpayer with 10,000 dollars income per year is paying about 30 tax dollars for space. The rest of his income, 9,970 dollars, remains for his subsistence, his recreation, his savings, his other taxes, and all his other expenditures。

You will probably ask now: "Why don't you take 5 or 3 or 1 dollar out of the 30 space dollars which the average American taxpayer is paying, and send these dollars to the hungry children?" To answer this question, I have to explain briefly how the economy of this country works. The situation is very similar in other countries. The government consists of a number of departments (Interior, Justice, Health, Education and Welfare, Transportation, Defense, and others) and the bureaus (National Science Foundation, National Aeronautics and Space Administration, and others). All of them prepare their yearly budgets according to their assigned missions, and each of them must defend its budget against extremely severe screening by congressional committees, and against heavy pressure for economy from the Bureau of the Budget and the President. When the funds 　　The budget of the National Aeronautics and Space Administration, naturally, can contain only items directly related to aeronautics and space. If this budget were not approved by Congress, the funds proposed for it would not be available for something else; they would simply not be levied from the taxpayer, unless one of the other budgets had obtained approval for a specific increase which would then absorb the funds not spent for space. You realize from this brief discourse that support for hungry children, or rather a support in addition to what the United States is already contributing to this very worthy cause in the form of foreign aid, can be obtained only if the appropriate department submits a budget line item for this purpose, and if this line item is then approved by Congress。

You may ask now whether I personally would be in favor of such a move by our government. My answer is an emphatic yes. Indeed, I would not mind at all if my annual taxes were increased by a number of dollars for the purpose of feeding hungry children, wherever they may live。

I know that all of my friends feel the same way. However, we could not bring such a program to life merely by desisting from making plans for voyages to Mars. On the contrary, I even believe that by working for the space program I can make some contribution to the relief and eventual solution of such grave problems as poverty and hunger on Earth. Basic to the hunger problem are two functions: the production of food and the distribution of food. Food production by agriculture, cattle ranching, ocean fishing and other large-scale operations is efficient in some parts of the world, but drastically deficient in many others. For example, large areas of land could be utilized far better if efficient methods of watershed control, fertilizer use, weather forecasting, fertility assessment, plantation programming, field selection, planting habits, timing of cultivation, crop survey and harvest planning were applied。

The best tool for the improvement of all these functions, undoubtedly, is the artificial Earth satellite. Circling the globe at a high altitude, it can screen wide areas of land within a short time; it can observe and measure a large variety of factors indicating the status and condition of crops, soil, droughts, rainfall, snow cover, etc., and it can radio this information to ground stations for appropriate use. It has been estimated that even a modest system of Earth satellites equipped with Earth resources, sensors, working within a program for worldwide agricultural improvements, will increase the yearly crops by an equivalent of many billions of dollars。

The distribution of the food to the needy is a completely different problem. The question is not so much one of shipping volume, it is one of international cooperation. The ruler of a small nation may feel very uneasy about the prospect of having large quantities of food shipped into his country by a large nation, simply because he fears that along with the food there may also be an import of influence and foreign power. Efficient relief from hunger, I am afraid, will not come before the boundaries between nations have become less divisive than they are today. I do not believe that space flight will accomplish this miracle over night. However, the space program is certainly among the most promising and powerful agents working in this direction。

Let me only remind you of the recent near-tragedy of Apollo 13. When the time of the crucial reentry of the astronauts approached, the Soviet Union discontinued all Russian radio transmissions in the frequency bands used by the Apollo Project in order to avoid any possible interference, and Russian ships stationed themselves in the Pacific and the Atlantic Oceans in case an emergency rescue would become necessary. Had the astronaut capsule touched down near a Russian ship, the Russians would undoubtedly have expended as much care and effort in their rescue as if Russian cosmonauts had returned from a space trip. If Russian space travelers should ever be in a similar emergency situation, Americans would do the same without any doubt。

Higher food production through survey and assessment from orbit, and better food distribution through improved international relations, are only two examples of how profoundly the space program will impact life on Earth. I would like to quote two other examples: stimulation of technological development, and generation of scientific knowledge。

The requirements for high precision and for extreme reliability which must be imposed upon the components of a moon-travelling spacecraft are entirely unprecedented in the history of engineering. The development of systems which meet these severe requirements has provided us a unique opportunity to find new material and methods, to invent better technical systems, to manufacturing procedures, to lengthen the lifetimes of instruments, and even to discover new laws of nature。

All this newly acquired technical knowledge is also available for application to Earth-bound technologies. Every year, about a thousand technical innovations generated in the space program find their ways into our Earthly technology where they lead to better kitchen appliances and farm equipment, better sewing machines and radios, better ships and airplanes, better weather forecasting and storm warning, better communications, better medical instruments, better utensils and tools for everyday life. Presumably, you will ask now why we must develop first a life support system for our moon-travelling astronauts, before we can build a remote-reading sensor system for heart patients. The answer is simple: significant progress in the solutions of technical problems is frequently made not by a direct approach, but by first setting a goal of high challenge which offers a strong motivation for innovative work, which fires the imagination and spurs men to expend their best efforts, and which acts as a catalyst by including chains of other reactions。

Spaceflight without any doubt is playing exactly this role. The voyage to Mars will certainly not be a direct source of food for the hungry. However, it will lead to so many new technologies and capabilities that the spin-offs from this project alone will be worth many times the cost of its implementation。

Besides the need for new technologies, there is a continuing great need for new basic knowledge in the sciences if we wish to improve the conditions of human life on Earth. We need more knowledge in physics and chemistry, in biology and physiology, and very particularly in medicine to cope with all these problems which threaten man's life: hunger, disease, contamination of food and water, pollution of the environment。

We need more young men and women who choose science as a career and we need better support for those scientists who have the talent and the determination to engage in fruitful research work. Challenging research objectives must be available, and sufficient support for research projects must be provided. Again, the space program with its wonderful opportunities to engage in truly magnificent research studies of moons and planets, of physics and astronomy, of biology and medicine is an almost ideal catalyst which induces the reaction between the motivation for scientific work, opportunities to observe exciting phenomena of nature, and material support needed to carry out the research effort。

Among all the activities which are directed, controlled, and funded by the American government, the space program is certainly the most visible and probably the most debated activity, although it consumes only 1.6 percent of the total national budget, and 3 per mille (less than one-third of 1 percent) of the gross national product. As a stimulant and catalyst for the development of new technologies, and for research in the basic sciences, it is unparalleled by any other activity. In this respect, we may even say that the space program is taking over a function which for three or four thousand years has been the sad prerogative of wars。

How much human suffering can be avoided if nations, instead of competing with their bomb-dropping fleets of airplanes and rockets, compete with their moon-travelling space ships! This competition is full of promise for brilliant victories, but it leaves no room for the bitter fate of the vanquished, which breeds nothing but revenge and new wars。

Although our space program seems to lead us away from our Earth and out toward the moon, the sun, the planets, and the stars, I believe that none of these celestial objects will find as much attention and study by space scientists as our Earth. It will become a better Earth, not only because of all the new technological and scientific knowledge which we will apply to the betterment of life, but also because we are developing a far deeper appreciation of our Earth, of life, and of man。

The photograph which I enclose with this letter shows a view of our Earth as seen from Apollo 8 when it orbited the moon at Christmas, 1968. Of all the many wonderful results of the space program so far, this picture may be the most important one. It opened our eyes to the fact that our Earth is a beautiful and most precious island in an unlimited void, and that there is no other place for us to live but the thin surface layer of our planet, bordered by the bleak nothingness of space. Never before did so many people recognize how limited our Earth really is, and how perilous it would be to tamper with its ecological balance. Ever since this picture was first published, voices have become louder and louder warning of the grave problems that confront man in our times: pollution, hunger, poverty, urban living, food production, water control, overpopulation. It is certainly not by accident that we begin to see the tremendous tasks waiting for us at a time when the young space age has provided us the first good look at our own planet。

Very fortunately though, the space age not only holds out a mirror in which we can see ourselves, it also provides us with the technologies, the challenge, the motivation, and even with the optimism to attack these tasks with confidence. What we learn in our space program, I believe, is fully supporting what Albert Schweitzer had in mind when he said: "I am looking at the future with concern, but with good hope."

My very best wishes will always be with you, and with your children。

Very sincerely yours,

Ernst Stuhlinger

Associate Director for Science

譯文：

1970年，贊比亞修女 Mary Jucunda 給 Ernst Stuhlinger 博士寫了一封信，他因在火星之旅工程中的原創(chuàng)性研究，成為 NASA(美國航空航天局)Marshall 太空航行中心的科學副總監(jiān)。信中，Mary Jucunda 修女問道：目前地球上還有這么多小孩子吃不上飯，他怎么能舍得為遠在火星的項目花費數(shù)十億美元。

Stuhlinger 很快給Jucunda 修女回了信，同時還附帶了一張題為“升起的地球”的照片，這張標志性的照片是宇航員 William Anders 于1968年在月球軌道上拍攝的(照片中可以看到月球的地面)。他這封真摯的回信隨后由 NASA 以《為什么要探索宇宙》為標題發(fā)表。

親愛的Mary Jucunda修女：

每天，我都會收到很多類似的來信，但這封對我的觸動最深，因為它來自一顆慈悲的飽含探求精神的心靈。我會盡自己所能來回答你這個問題。

首先，請允許我向你以及你勇敢的姐妹們表達深深的敬意，你們獻身于人類最崇高的事業(yè)：幫助身處困境的同胞。

在來信中，你問我在目前地球上還有兒童由于饑餓面臨死亡威脅的情況下，為什么還要花費數(shù)十億美元來進行飛向火星的航行。我清楚你肯定不希望這樣的答案：“哦，我之前不知道還有小孩子快餓死了，好吧，從現(xiàn)在開始，暫停所有的太空項目，直到孩子們都吃上飯再說。”事實上，早在人類的技術(shù)水平可以暢想火星之旅之前，我已經(jīng)對兒童的饑荒問題有所了解。而且，同我很多朋友的看法一樣，我認為此時此刻，我們就應該開始通往月球、火星乃至其他行星的偉大探險。從長遠來看，相對于那些要么只有年復一年的辯論和爭吵，要么連妥協(xié)之后也遲遲無法落實的各種援助計劃來說，我甚至覺得探索太空的工程給更有助于解決人類目前所面臨的種種危機。

在詳細說明我們的太空項目如何幫助解決地面上的危機之前，我想先簡短講一個真實的故事。那是在400年前，德國某小鎮(zhèn)里有一位伯爵。他是個心地善良的人，他將自己收入的一大部分捐給了鎮(zhèn)子上的窮人。這十分令人欽佩，因為中世紀時窮人很多，而且那時經(jīng)常爆發(fā)席卷全國的瘟疫。一天，伯爵碰到了一個奇怪的人，他家中有一個工作臺和一個小實驗室，他白天賣力工作，每天晚上的幾小時的時間專心進行研究。他把小玻璃片研磨成鏡片，然后把研磨好的鏡片裝到鏡筒里，用此來觀察細小的物件。伯爵被這個前所未見的可以把東西放大觀察的小發(fā)明迷住了。他邀請這個怪人住到了他的城堡里，作為伯爵的門客，此后他可以專心投入所有的時間來研究這些光學器件。

然而，鎮(zhèn)子上的人得知伯爵在這么一個怪人和他那些無用的玩意兒上花費金錢之后，都很生氣。“我們還在受瘟疫的苦，”他們抱怨道，“而他卻為那個閑人和他沒用的愛好亂花錢!”伯爵聽到后不為所動。“我會盡可能地接濟大家，”他表示，“但我會繼續(xù)資助這個人和他的工作，我確信終有一天會有回報。”

果不其然，他的工作(以及同時期其他人的努力)贏來了豐厚的回報：顯微鏡。顯微鏡的發(fā)明給醫(yī)學帶來了前所未有的發(fā)展，由此展開的研究及其成果，消除了世界上大部分地區(qū)肆虐的瘟疫和其他一些傳染性疾病。

伯爵為支持這項研究發(fā)明所花費的金錢，其最終結(jié)果大大減輕了人類所遭受的苦難，這回報遠遠超過單純將這些錢用來救濟那些遭受瘟疫的人。

我們目前面臨類似的問題。美國總統(tǒng)的年度預算共有2000億美元，這些錢將用于醫(yī)療、教育、福利、城市建設、高速公路、交通運輸、海外援助、國防、環(huán)保、科技、農(nóng)業(yè)以及其他多項國內(nèi)外的工程。今年，預算中的1.6%將用于探索宇宙，這些花銷將用于阿波羅以計劃、其他一些涵蓋了天體物理學、深空天文學、空間生物學、行星探測工程、地球資源工程的小項目以及空間工程技術(shù)。為擔負這些太空項目的支出，平均每個年收入10,000美元的美國納稅人需要支付約30美元給太空，剩下的9,970美元則可用于一般生活開支、休閑娛樂、儲蓄、別的稅項等花銷。

也許你會問：“為什么不從納稅人為太空支付的30美元里抽出5美元或3美元或是1美元來救濟饑餓的兒童呢?”為了回答這個問題，我需要先簡單解釋一下我們國家的經(jīng)濟是如何運行的，其他國家也是類似的情形。政府由幾個部門(如內(nèi)政部、司法部、衛(wèi)生部與公眾福利部、教育部、運輸部、國防部等)和幾個機構(gòu)(國家科學基金會、國家航空航天局等)組成，這些部門和機構(gòu)根據(jù)自己的職能制定相應的年度預算，并嚴格執(zhí)行以應對國務委員會的監(jiān)督，同時還要應付來自預算部門和總統(tǒng)對于其經(jīng)濟效益的壓力。當資金最終由國會撥出后，將嚴格用于經(jīng)預算批準的計劃中的項目。

顯然，NASA的預算中所包含的項目都是和航空航天有關的。未經(jīng)國會批準的預算項目，是不會得到資金支持的，自然也不會被課稅，除非有其他部門的預算涵蓋了該項目，借此花掉沒有分配給太空項目的資金。由這段簡短的說明可以看出，要想援助饑餓的兒童，或在美國已有的對外援助項目上增加援助金額，需要首先由相關部門提出預算，然后由國會批準才行。

要問是否同意政府實施類似的政策，我個人的意見是絕對贊成。我完全不介意每年多付出一點點稅款來幫助饑餓的兒童，無論他們身在何處。

我相信我的朋友們也會持相同的態(tài)度。然而，事情并不是僅靠把去往火星航行的計劃取消就能輕易實現(xiàn)的。相對的，我甚至認為可以通過太空項目，來為緩解乃至最終解決地球上的貧窮和饑餓問題作出貢獻。解決饑餓問題的關鍵有兩部分：食物的生產(chǎn)和食物的發(fā)放。食物的生產(chǎn)所涉及的農(nóng)業(yè)、畜牧業(yè)、漁業(yè)及其他大規(guī)模生產(chǎn)活動在世界上的一些地區(qū)高效高產(chǎn)，而在有的地區(qū)則產(chǎn)量嚴重不足。通過高科技手段，如灌溉管理，肥料的使用，天氣預報，產(chǎn)量評估，程序化種植，農(nóng)田優(yōu)選，作物的習性與耕作時間選擇，農(nóng)作物調(diào)查及收割計劃，可以顯著提高土地的生產(chǎn)效率。

人造地球衛(wèi)星無疑是改進這兩個關鍵問題最有力的工具。在遠離地面的運行軌道上，衛(wèi)星能夠在很短的時間里掃描大片的陸地，可以同時觀察計算農(nóng)作物生長所需要的多項指標，土壤、旱情、雨雪天氣等等，并且可以將這些信息廣播至地面接收站以便做進一步處理。事實證明，配備有土地資源傳感器及相應的農(nóng)業(yè)程序的人造衛(wèi)星系統(tǒng)，即便是最簡單的型號，也能給農(nóng)作物的年產(chǎn)量帶來數(shù)以十億美元計的提升。

如何將食品發(fā)放給需要的人則是另外一個全新的問題，關鍵不在于輪船的容量，而在于國際間的合作。小國統(tǒng)治者對于來自大國的大量食品的輸入會感到很困擾，他們害怕伴隨著食物一同而來的還有外國勢力對其統(tǒng)治地位的影響�？峙略趪�與國之間消除隔閡之前，饑餓問題無法得以高效解決了。我不認為太空計劃能一夜之間創(chuàng)造奇跡，然而，探索宇宙有助于促使問題向著良好的方向發(fā)展。

以最近發(fā)生的阿波羅13號事故為例。當宇航員處于關鍵的大氣層再入期時，為了保證通訊暢通，蘇聯(lián)關閉了境內(nèi)與阿波羅飛船所用頻帶相同的所有廣播通信。同時派出艦艇到太平洋和大西洋海域以備第一時間進行搜救工作。如果宇航員的救生艙降落到俄方艦船附近，俄方人員會像對待從太空返回的本國宇航員一樣對他們進行救助。同樣，如果俄方的宇宙飛船遇到了類似的緊急情況，美國也一定會毫不猶豫地提供援助。

通過衛(wèi)星進行監(jiān)測與分析來提高食品產(chǎn)量，以及通過改善國際關系提高食品發(fā)放的效率，只是通過太空項目提高人類生活質(zhì)量的兩個方面。下面我想介紹另外兩個重要作用：促進科學技術(shù)的發(fā)展和提高一代人的科學素養(yǎng)。

登月工程需要歷史上前所未有的高精度和高可靠性。面對如此嚴苛的要求，我們要尋找新材料，新方法;開發(fā)出更好的工程系統(tǒng);用更可靠的制作流程;讓儀器的工作壽命更長久;甚至需要探索全新的自然規(guī)律。

這些為登月發(fā)明的新技術(shù)同樣可以用于地面上的工程項目。每年，都有大概一千項從太空項目中發(fā)展出來的新技術(shù)被用于日常生活中，這些技術(shù)打造出更好的廚房用具和農(nóng)場設備，更好的縫紉機和收音機，更好的輪船和飛機，更精確的天氣預報和風暴預警，更好的通訊設施，更好的醫(yī)療設備，乃至更好的日常小工具。你可能會問，為什么先設計出宇航員登月艙的維生系統(tǒng)，而不是先為心臟病患者造出遠程體征監(jiān)測設備呢。答案很簡單：解決工程問題時，重要的技術(shù)突破往往并不是按部就班直接得到的，而是來自能夠激發(fā)出強大創(chuàng)新精神，能夠燃起的想象力和堅定的行動力，以及能夠整合好所有資源的充滿挑戰(zhàn)的目標。

太空旅行無可置疑地是一項充滿挑戰(zhàn)的事業(yè)。通往火星的航行并不能直接提供食物解決饑荒問題。然而，它所帶來大量的新技術(shù)和新方法可以用在火星項目之外，這將產(chǎn)生數(shù)倍于原始花費的收益。

若希望人類生活得越來越好，除了需要新的技術(shù)，我們還需要基礎科學不斷有新的進展。包括物理學和化學，生物學和生理學，特別是醫(yī)學，用來照看人類的健康，應對饑餓、疾病、食物和水的污染以及環(huán)境污染等問題。

我們需要更多的年輕人投入到科學事業(yè)中來，我們需要給予那些投身科研事業(yè)的有天分的科學家更多的幫助。隨時要有富于挑戰(zhàn)的研究項目，同時要保證對項目給予充分的資源支持。在此我要重申，太空項目是科技進步的催化劑，它為學術(shù)研究工作提供了絕佳和實踐機會，包括對月球和其他行星的研究、物理學和天文學、生物學和醫(yī)學科學等學科，有它，科學界源源不斷出現(xiàn)令人激動不已研究課題，人類得以窺見宇宙無比瑰麗的景象;為了它，新技術(shù)新方法不斷涌現(xiàn)。

由美國政府控制并提供資金支持的所有活動中，太空項目無疑最引人矚目也最容易引起爭議，盡管其僅占全部預算的1.6%，不到全民生產(chǎn)總值的千分之三。作為新技術(shù)的驅(qū)動者和催化劑，太空項目開展了多項基礎科學的研究，它的地位注定不同于其他活動。從某種意義上來說，以太空項目的對社會的影響，其地位相當于3-4千年前的戰(zhàn)爭活動。

如果國家之間不再比拼轟炸機和遠程導彈，取而代之比拼月球飛船的性能，那將避免多少戰(zhàn)亂之苦!聰慧的勝利者將滿懷希望，失敗者也不用飽嘗痛苦，不再埋下仇恨的種子，不再帶來復仇的戰(zhàn)爭。

盡管我們開展的太空項目研究的東西離地球很遙遠，已經(jīng)將人類的視野延伸至月亮、至太陽、至星球、直至那遙遠的星辰，但天文學家對地球的關注，超過以上所有天外之物。太空項目帶來的不僅有那些新技術(shù)所提供的生活品質(zhì)的提升，隨著對宇宙研究的深入，我們對地球，對生命，對人類自身的感激之情將越深。太空探索讓地球更美好。

隨信一塊寄出的這張照片，是1968年圣誕節(jié)那天阿波羅8號在環(huán)月球軌道上拍攝的地球的景象。太空項目所能帶來的各種結(jié)果中，這張照片也許是其中最可貴的一項。它開闊了人類的視野，讓我們?nèi)绱酥庇^地感受到地球是廣闊無垠的宇宙中如此美麗而又珍貴的孤島，同時讓我們認識到地球是我們唯一的家園，離開地球就是荒蕪陰冷的外太空。無論在此之前人們對地球的了解是多么的有限，對于破壞生態(tài)平衡的嚴重后果的認識是多么的不充分。在這張照片公開發(fā)表之后，面對人類目前所面臨的種種嚴峻形勢，如環(huán)境污染、饑餓、貧窮、過度城市化、糧食問題、水資源問題、人口問題等等，號召大家正視這些嚴重問題的呼聲越來越多。人們突然表示出對自身問題的關注，不能說和目前正在進行的這些初期太空探索項目，以及它所帶來的對于人類自身家園的全新視角無關。

太空探索不僅僅給人類提供一面審視自己的鏡子，它還能給我們帶來全新的技術(shù)，全新的挑戰(zhàn)和進取精神，以及面對嚴峻現(xiàn)實問題時依然樂觀自信的心態(tài)。我相信，人類從宇宙中學到的，充分印證了Albert Schweitzer那句名言：“我憂心忡忡地看待未來，但仍滿懷美好的希望。”

向您和您的孩子們致以我最真摯的敬意!

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恩斯特·史都林格