NASA just embarked upon its most ambitious Mars mission to date, spending a whopping $2.5 billion on this 1-ton rover, hoping to find some evidence as to whether or not Mars once supported life.

At the same time, a United Nations report noted that there were 870 million undernourished people in the world (defined as “a state of energy deprivation” for more than a year). Even if all food production and distribution goals are met, 12.5 percent of the world will be undernourished in 2015. On a planet that also has more than a billion people living in destitute poverty, can we justify spending so much on another one?

Abraham Joshua Heschel (The Moral Dilemma of the Space Age) said it well:

I challenge the high value placed on the search for extraterrestrial life only because it is being made at the expense of life and humanity here on earth. …Is the discovery of some form of life on Mars or Venus or man’s conquest of the moon really as important to humanity as the conquest of poverty, disease, prejudice, and superstition? Of what value will it be to land a few men on the wilderness of the moon if we neglect the needs of millions of men on earth? The conflict we face is between the exploration of space and the more basic needs of the human race. In their contributions to its resolution, religious leaders and teachers have an obligation to challenge the dominance of science over human affairs. They must defy the establishment of science as G-d. It is an instrument of G-d which we must not permit to be misused.

Proponents of the space program and NASA’s current $17.7 billion budget (and $300 billion collectively spent by all countries) point to technological advances that have come about or accelerated as a result of the space program:

• Satellite television and the mobile telephone
• Global positioning system (GPS) technology
• Virtual reality devices
• Extremely accurate maps
• Advances in digital imaging that have improved screening methods of existing technology (e.g., improved MRI, CT scans, and breast cancer screening)

There are also elements that cannot be quantified, such as the use of the photograph of Earth taken from space that was used to promote environmentalism, or the effect of the space program in promoting science in schools. As astronomer Neil deGrasse Tyson stated: “You don't have to set up a program to convince people that being an engineer is cool. They'll know it just by the cultural presence of those activities. You do that, and it'll jump-start our dreams." There are a lot of benefits to space travel and galaxy exploration.

Currently, NASA has about 100 space programs ranging from examining the Earth’s atmosphere, measuring the planet’s water cycle, and tracking hurricanes and storms, to exploring asteroids and planets. Many scientists consider these ongoing programs to be vital to the advance of science and understanding our planet and the universe.

On the other hand, the American space program grew out of the Cold War anxiety over the Soviet Union’s success in launching the Sputnik satellite, and much of this program has had military intentions. Nor should it be forgotten that the United States used former Nazi scientists who had developed the dreaded V2 rocket (some of whom worked in facilities that starved their slave laborers). While the program had a spectacular success in landing a man on the moon in 1969, it also led to the creation of weapons like the inter-continental ballistic missile and multiple independent reentry vehicle. These “advances” enabled a single missile to carry up to 10 nuclear warheads thousands of miles, creating the potential for annihilating all human life on Earth. Thus, the space program has had mixed results.

Many believe that we are searching for extra-terrestrial life. This reality is not impossible according to Jewish thought. There is a Jewish theological basis to accept that there are other worlds in existence. “‘There was evening and there was morning, the first day’ (Bereshit 1:5): From here (we learn that) the Holy One, Blessed is He, created worlds and destroyed them, until G-d created these. G-d said: These give me pleasure, but those did not give me pleasure” (Bereshit Rabbah 3:7).

Rav Saadia Gaon taught that we live in a centripetal Platonic notion of the universe, where everything moves toward the center (toward the human). This is an anthropocentric approach (i.e., that humans occupy the central position of existence, and that everything should be interpreted for its effect on humans). The Rambam, however, taught that we live in a centrifugal universe of Aristotelian values. The Rambam rejects anthropocentricism with the teleological position that G-d creates everything for its own purpose (Mishlei 16:4, “l’maanehu”—for the sake of G-d as opposed to for the sake of man), and thus the universe is centrifugal (everything moving away from the center), and the value of all increases as it goes outwards from man, Earth, into the “active intellect,” and beyond.

The science of both thinkers is known to be incorrect today, but there is still philosophical value to their approaches. In our own time an important Jewish philosopher, Rabbi Norman Lamm, followed in the school of the Rambam and wrote: “There is no need to exaggerate man’s importance, and to exercise a kind of racial or global arrogance, in order to discover the sources of man’s significance and uniqueness.”

Although “there is no need to exaggerate man’s importance” and there is a lot of value in expanding our knowledge of the universe around us both for knowledge’s sake and for the forward march of technology that advances the cause of human sustainability, on balance it is clear that the noble goal of reaching out into the cosmos must play second fiddle to the nobler goal of continued life on the only planet we call home. We must be invested in science and discovery and long-term growth but we must also remember that our main priorities are addressing the human needs of today in this world.

Rabbi Shmuly Yanklowitz is the Founder and President of Uri L'Tzedek, the Senior Rabbi at Kehilath Israel, and is the author of "Jewish Ethics & Social Justice: A Guide for the 21st Century." Newsweek named Rav Shmuly one of the top 50 rabbis in America!"