• Looking For Life
    Enceladus: The next frontier in adventure travel.

    Image courtesy David Seal/NASA

    Space Search
    It all comes back to the human imagination and curiosity and just getting captivated by looking up at the night sky as a young kid. I grew up in a small town in Vermont and had the great fortune to be exposed to a beautiful night sky.
    Kevin Hand, astrobiologist

    Cosmos Education
    Kevin Hands work with Cosmos Education may seem far removed from his work as an astrobiologist, but he says the organization is simply encouraging the next generation of science teachers, doctors, and scientists. Cosmos Education works primarily with schools in Kenya and Zambia to foster critical thinking skills across a wide variety of scientific disciplines. The hands-on activities may include studies on HIV/AIDS care and prevention, basic chemistry labs, and even lessons on how soap is manufactured.

    "It's important to Cosmos Education that local leaders guide the program. I'm a white guy from the United States, the poster boy of [contemporary] science," Kevin says. "Local mentors can provide better leadership. Their stories, about what they do and how they got there, help students see themselves succeeding in these fields."

    By Stuart Thornton

    Monday, October 24, 2011

    National Geographic Emerging Explorer Kevin Hand has traveled to the extremes of the Earth to better understand how life might exist in outer space.

    Hand, the deputy chief scientist for solar system exploration at NASA’s Jet Propulsion Laboratory in Pasadena, California, has spent time on Battleship Promontory, Antarctica, traveled far north to Barrow, Alaska, and been deep in the Mid-Atlantic Ridge. If life can exist in these frigid places, he reasons, it might also exist on Jupiter’s moon Europa or Saturn’s moon Enceladus, for example.

    “One big-picture aspect is understanding the constraints of habitability for life as we know it,” Hand says. “So we study and understand the limits of habitability here on Earth, so that we can better identify and explore potentially habitable environments elsewhere, whether that’s Europa or Mars or Enceladus.”

    But even a cold day in Antarctica doesn’t reach the temperature of Europa, at -173 degrees Celsius (-280-degree Fahrenheit).

    “No place on Earth compares to the surface of Europa,” Hand says.

    So scientists are hoping to study the moon up close. NASA is currently planning a mission to Europa and three other moons of Jupiter. Hand helps design spacecraft and equipment for the mission, and he tests some early versions of these tools in Earth’s extreme regions.

    “When we go out into these environments, we also use some of the tools and techniques that are being developed or deployed on the spacecraft, and that will provide the data for us when we land rovers and spacecraft on these worlds,” he says. “The approach is sort of twofold from understanding the limits of life on Earth and understanding how to utilize the techniques and technology to study that life both here and beyond.”

    Lost City

    One of Hand’s most fruitful expeditions found him in the middle of the Atlantic Ocean. Hand descended in a submersible to investigate a unique underwater feature known as the “Lost City.” The “city” is actually a collection of carbonate towers that looks like a cathedral. Carbonate is a material produced as seawater interacts with vent fluid ejected by the region’s hydrothermal vents.

    More than a kilometer beneath the surface of the ocean, where light does not reach, bacteria in Lost City cannot use photosynthesis to create energy. They use a process called chemosynthesis, which uses materials found in vent fluid.

    Hand believes places like Lost City can provide valuable clues about how life might exist on Europa. The moon is covered in ice, and scientists think there is a liquid ocean beneath its crust. Light and photosynthesis would not be available to life on Europa.

    “The exciting aspect of hydrothermal vents in the context of astrobiology is that there are ecosystems operating independent or not directly powered by photosynthesis,” he says. “They are utilizing chemosynthesis at the base of the food chain.”

    Places like Lost City also help Hand determine where to begin looking for life on Europa.

    “If Europa is being tugged and pulled and squeezed through the tidal interaction with Jupiter, then there’s good reason to believe that the seafloor of Europa might be somewhat active and may host some hydrothermal vents,” he says. “And if Europa has hydrothermal vents, that’s a great place for providing the chemistry needed for life. So those would be the types of environments that we would want to go and explore.”

    Extraterrestrial Oceans

    The possibility of liquid oceans on Europa and Enceladus has spurred scientists to focus on the two moons in their search for life in outer space.

    “If we have learned anything about life on Earth,” Hand says, “it’s that where you find water, you generally find life.”

    Hand believes Europa holds the best possibility of life.

    “When we think of priorities of next missions, I champion Europa because I think the science of Europa is mature,” he says. “We understand Europa quite well in terms of the geophysical models and the reason why it has an ocean.”

    Hand says Europa seems to have a lot of water, despite its relatively small size.

    “Europa is quite a bit smaller than the Earth, but the 100-kilometer-deep liquid water ocean ends up containing two to three times the volume of all the liquid water on Earth,” he says.

    Even if NASA launches a probe to Europa in 2020, it would take another eight years for the spacecraft to reach the moon. But Hand puts the seemingly long wait into perspective.

    “When you think about it on our day-to-day scale, it seems like a long time,” he says. “But when you think about the history of humanity and how long humans have been asking this question, it’s really the blink of an eye. It’s quite exciting that I’m alive during the time period when we have the technological capability to go out and not just ask these questions but also potentially answer them.”

  • Term Part of Speech Definition Encyclopedic Entry
    astrobiologist Noun

    person who studies the possibility of life in outer space.

    bacteria Plural Noun

    (singular: bacterium) single-celled organisms found in every ecosystem on Earth.

    capability Noun

    ability to perform a task.

    carbonate adjective, noun

    mineral created by the action of carbon dioxide on a base.

    cathedral Noun

    important regional church.

    chemosynthesis Noun

    process by which some microbes turn carbon dioxide and water into carbohydrates using energy obtained from inorganic chemical reactions.

    city Noun

    large settlement with a high population density.

    constraint Noun

    limitation or obstacle.

    data Plural Noun

    (singular: datum) information collected during a scientific study.

    deploy Verb

    to move military troops, support personnel, and equipment.

    Earth Noun

    our planet, the third from the Sun. The Earth is the only place in the known universe that supports life.

    Encyclopedic Entry: Earth
    ecosystem Noun

    community and interactions of living and nonliving things in an area.

    Encyclopedic Entry: ecosystem
    eject Verb

    to get rid of or throw out.

    Emerging Explorer Noun

    an adventurer, scientist, innovator, or storyteller recognized by National Geographic for their visionary work while still early in their careers.

    Enceladus Noun

    moon of the planet Saturn.

    energy Noun

    capacity to do work.

    equipment Noun

    tools and materials to perform a task or function.

    Europa Noun

    moon of Jupiter.

    expedition Noun

    journey with a specific purpose, such as exploration.

    extreme environment Noun

    ecosystem whose characteristics make it difficult to support life.

    food chain Noun

    group of organisms linked in order of the food they eat, from producers to consumers, and from prey, predators, scavengers, and decomposers.

    Encyclopedic Entry: food chain
    frigid Adjective

    very cold.

    fruitful Adjective

    good and beneficial results.

    geophysical Adjective

    having to do with geology and the physics of the Earth and its atmosphere.

    habitability Noun

    suitability to support life.

    hydrothermal Adjective

    related to hot water, especially water heated by the Earth's internal temperature.

    ice Noun

    water in its solid form.

    Encyclopedic Entry: ice
    Jet Propulsion Laboratory (JPL) Noun

    NASA center that focuses on robotic exploration of the solar system.

    Jupiter Noun

    largest planet in the solar system, the fifth planet from the Sun.

    Lost City Noun

    field of hydrothermal vents along the seafloor near the Mid-Atlantic Ridge.

    Mars Noun

    fourth planet from the sun, between Earth and Jupiter.

    mature Adjective

    adult member of a species who is able to reproduce.

    Mid-Atlantic Ridge Noun

    underwater mountain range that runs from Iceland to Antarctica.

    moon Noun

    natural satellite of a planet.

    Encyclopedic Entry: moon
    NASA Noun

    (acronym for National Aeronautics and Space Administration) U.S. agency responsible for space research and systems.

    organism Noun

    living or once-living thing.

    outer space Noun

    space beyond Earth's atmosphere.

    photosynthesis Noun

    process by which plants turn water, sunlight, and carbon dioxide into water, oxygen, and simple sugars.

    potential Noun


    region Noun

    any area on the Earth with one or more common characteristics. Regions are the basic units of geography.

    Encyclopedic Entry: region
    rover Noun

    vehicle that remotely explores a region, such as the surface of a moon, planet, or other celestial body.

    Saturn Noun

    sixth planet from the sun.

    seafloor Noun

    surface layer of the bottom of the ocean.

    seawater Noun

    salty water from an ocean or sea.

    solar system Noun

    the sun and the planets, asteroids, comets, and other bodies that orbit around it.

    spacecraft Noun

    vehicle designed for travel outside Earth's atmosphere.

    spur Verb

    to encourage or move forward.

    submersible Noun

    small submarine used for research and exploration.

    technique Noun

    method of doing something.

    technology Noun

    the science of using tools and complex machines to make human life easier or more profitable.

    temperature Noun

    degree of hotness or coldness measured by a thermometer with a numerical scale.

    Encyclopedic Entry: temperature
    tidal interaction Noun

    mutual gravitational attraction of two bodies.

    tool Noun

    instrument used to help in the performance of a task.

    twofold Adjective

    having two parts or layers

    unique Adjective

    one of a kind.

    utilize Verb

    to use.

    valuable Adjective

    worth a considerable amount of money or esteem.

    vast Adjective

    huge and spread out.

    vent Noun

    crack in the Earth's crust that spews hot gases and mineral-rich water.

    vent fluid Noun

    chemicals ejected by hydrothermal vents.

    volume Noun

    space an object occupies.

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