From the time of our birth, humans have felt a primordial urge to explore -- to blaze new trails, map new lands, and answer profound questions about ourselves and our universe.

    Now, as America charts a new course into the cosmos, NASA's History Office offers a broad perspective in a series of essays titled "Why We Explore." Drawing parallels to the Age of Discovery in the 15th and 16th centuries, NASA Chief Historian Steven J. Dick writes about our current Age of Space, "a continuous story of voyages further and further from the home planet."

Moon, Mars and Beyond

    lunar lander

    Concept of a future moon landing. Credit: NASA/John Frassanito and Associates

    Moon: By going to the moon for extended periods of time, astronauts will search for resources and learn how to work safely in a harsh environment -- stepping stones to future exploration. The moon also offers many clues about the time when the planets were formed.

    Mars: Robotic missions have found evidence of a watery past, suggesting that simple life forms may have developed long ago and may persist beneath the surface today. Human exploration could provide answers to some profound questions.

    Beyond: As humans and robots work together exploring the moon and Mars, NASA spacecraft will continue to send back scientific data from throughout the solar system, laying the groundwork for potential human journeys.

Why We Explore

  • T. Keith Glennan, Administrator

    The Birth of NASA

    It may well be argued that NASA has become the world's premier agent for exploration, carrying on in "the new ocean" of outer space a long tradition of expanding the physical and mental boundaries of humanity.

  • The three men responsible for Explorer 1, America's first Earth satellite, from left to right are William H. Pickering, James A. van Allen and Wernher von Braun.

    A Moment in Time: Explorer 1

    The year 2008 will be a year of 50th anniversaries for space exploration. Following in the wake of Sputnik I and Sputnik II, on January 31, 1958 the United States launched Explorer 1.

  • Phobos

    Under the Moons of Mars

    A recent conference on the moons of Mars reminded me of the wonders that await us even in our own solar system.

  • A composite of the Jovian system, includes the edge of Jupiter with its Great Red Spot, and two of Jupiter's four largest moons, known as the Galilean satellites.

    Mission to Jupiter

    Galileo represented a new phase in the study of the outer planets. Pioneer and Voyagers 1 and 2 together completed the preliminary reconnaissance of those gas giants, but Galileo undertook a much more systematic, in-depth and holistic analysis of the entire Jupiter system.

  • Voyager 1 and 2 spacecraft

    Voyages Beyond the Solar System: The Voyager Interstellar Mission

    Originally planned to explore the gas giant planets and their satellites, the Voyager spacecraft have continued their journeys and are now the most distant human objects in the cosmos.

Mission Information