Browse Archive

  • 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.

  • John Mather, 2006 Nobel Prize Winner for Physics

    Voyages to the Beginning of Time

    The recent award of the Nobel Prize in Physics to NASA astrophysicist John Mather and University of California Berkeley astrophysicist George Smoot reminds us that NASA not only undertakes voyages in space, but also in time.

  • Pluto, center and it's previously known moon Charon

    Pluto, Classification and Exploration

    The universe is what it is, not what we want it to be, and science must always be open to correcting its mistakes.

  • This global view of the surface of Venus is centered at 0 degrees east longitude.

    Voyages to the Planets: Venus

    Less than a century ago, the planet Venus was most often referred to as "Earth's sister planet."

  • Project Mercury Astronauts

    The Voyagers

    Exploration doesn't happen by sitting still, physically or intellectually.

  • Astronaut Edwin E.

    The Voyages of Apollo

    No single essay can do justice to the events that took place between 1968 and 1972, four years that, as time passes, seem all the more remarkable for human history.

  • Voyage to the Moon

    Voyages to the Moon: Robotic Reconnaissance

    It is hardly cause for surprise that with the beginning of the Space Age humans set their sights on the nearest celestial body, the Moon.

  • These color images of Eros was acquired by NEAR on February 12, 2000, at a range of 1800 kilometers (1100 miles) during the final approach imaging sequence prior to orbit insertion.

    Voyages to the Asteroids

    Daring though voyages to comets have been, with comet material often pelting and even damaging passing spacecraft, voyages to asteroids have gone one step further, achieving an actual landing, or maybe two landings.

  • Deep Impact

    Voyages to Comets

    Among the more adventurous voyages of exploration are those whose destinations are comets.

  • The Sun is indeed our nearest star, a mere 8 light minutes away, compared to 4.5 light years for the next star, the Alpha Centauri system. A nuclear furnace generating prodigious amounts of energy, the Sun provides the conditions necessary for life on Earth. It is a matter of practical importance that we know how the Sun works, as well as a matter of theoretical importance, since its proximity gives us the best information on how other Sun-like stars work.

    Voyages to the Sun

    Humanity's epic voyages to the Moon are well known, the stuff of history. But what about voyages to the Sun?

  • Great Images at NASA: Orion

    Discovering New Worlds

    In October 1995 - ten years ago this month - two Swiss astronomers announced the discovery of the first planet around a Sun-like star outside of our solar system.

  • Risk and Exploration Revisited

    Risk and Exploration Revisited

    Exploration is necessary for a creative society and risk is the inevitable companion of exploration.

  • Cosmic evolution is depicted in this image from the exobiology program at NASA Ames Research Center, 1986. Cosmic evolution begins (upper left) with the formation of stars and planetary systems, proceeds (bottom) to primitive and complex life, and culminates with intelligence, technology and astronomers (upper right) contemplating the universe.

    Our Place in the Universe

    The study of cosmic evolution allows us to see the universe as it really is, to reflect on our place in it, and to "know the place for the first time."

  • First picture clearly showing craters on Mars

    The Search for Life

    Why do we explore? Since the beginning of the Space Age one of the chief drivers has been the search for life beyond Earth.

  • Image of Mars from Spirit rover

    Exploration and Science

    Human exploration is more than the sum of all science.

  • Jesco von Puttkamer, Boris Chertok, and Steven J. Dick

    International Cooperation

    One of the benefits of space exploration is international cooperation.

  • Capture of Intelsat VI

    Societal Impact of the Space Age

    As controversies swirl about funding, resources, motives and methods for spaceflight, it is well to consider the consequences of exploring space – and of choosing not to do so.