Derelict satellites, equipment and other debris orbiting Earth (aka space junk) have been accumulating for many decades and could damage or even possibly destroy satellites and human spacecraft if they collide. During the past 50 years, various National Aeronautics and Space Administration (NASA) communities have contributed significantly to maturing meteoroid and orbital debris (MMOD) programs to their current state. Satellites have been redesigned to protect critical components from MMOD damage by moving critical components from exterior surfaces to deep inside a satellite's structure. Orbits are monitored and altered to minimize the risk of collision with tracked orbital debris. MMOD shielding added to the International Space Station (ISS) protects critical components and astronauts from potentially catastrophic damage that might result from smaller, untracked debris and meteoroid impacts. Limiting Future Collision Risk to Spacecraft: An Assessment of NASA's Meteoroid and Orbital Debris Program examines NASA's efforts to understand the meteoroid and orbital debris environment, identifies what NASA is and is not doing to mitigate the risks posed by this threat, and makes recommendations as to how they can improve their programs. While the report identified many positive aspects of NASA's MMOD programs and efforts including responsible use of resources, it recommends that the agency develop a formal strategic plan that provides the basis for prioritizing the allocation of funds and effort over various MMOD program needs. Other necessary steps include improvements in long-term modeling, better measurements, more regular updates of the debris environmental models, and other actions to better characterize the long-term evolution of the debris environment.

Explores how comets, meteors, and asteroids move through our solar system, and explains the ingredients that make a comet's tail and other topics

Meteor Showers and their Parent Comets is a unique handbook for astronomers interested in observing meteor storms and outbursts. Spectacular displays of 'shooting stars' are created when the Earth's orbit crosses a meteoroid stream, as each meteoroid causes a bright light when it enters our atmosphere at high speed. Jenniskens, an active meteor storm chaser, explains how meteoroid streams originate from the decay of meteoroids, comets and asteroids, and how they cause meteor showers on Earth. He includes the findings of recent space missions to comets and asteroids, the risk of meteor impacts on Earth, and how meteor showers may have seeded the Earth with ingredients that made life possible. All known meteor showers are identified, accompanied by fascinating details on the most important showers and their parent comets. The book predicts when exceptional meteor showers will occur over the next fifty years, making it a valuable resource for both amateur and professional astronomers.

Leading specialists in various disciplines were first invited to a multidisciplinary workshop funded by ICSU on the topic to gain a better appreciation and perspective on the subject of comet/asteroid impacts as viewed by different disciplines. This volume provides a necessary link between various disciplines and comet/asteroid impacts.

In 1993, the U.S. Department of Defense declassified information dealing with frequent explosions in the upper atmosphere caused by meteoric impact. It is estimated that impacts have occurred of a magnitude equivalent to the atomic bomb detonated at Hiroshima. Not all such space voyagers meet their end in the atmosphere, however; huge craters attest to the bombardment of earth over millions of years, and a major impact may have resulted in the extinction of dinosaurs. An impact in Siberia near the beginning of this century proves that such events are not confined to geologic time. Hazards Due to Comets and Asteroids marks a significant step in the attempt to come to grips with the threats posed by such phenomena. It brings together more than one hundred scientists from around the world, who draw on observational and theoretical research to focus on the technical problems related to all aspects of dealing with these hazards: searching for and identifying hazardous comets and asteroids; describing their statistics and characteristics; intercepting and altering the orbits of dangerous objects; and applying existent technologies—rocket boosters, rendezvous and soft-landing techniques, instrumentation—to such missions. The book considers defensive options for diverting or disrupting an approaching body, including solar sails, kinetic-energy impacts, nuclear explosives, robotic mass drivers, and various propulsion systems. A cataclysmic impact posing a threat to life on Earth is a possibility that tomorrow's technology is capable of averting. This book examines in depth the reality of the threat and proposes practical measures that can be initiated now should we ever need to deal with it.

'Astonishing' - New Scientist Icy, rocky, sometimes dusty, always mysterious – comets and asteroids are among the Solar System's very oldest inhabitants, formed within a swirling cloud of gas and dust in the area of space that eventually hosted the Sun and its planets. Locked within each of these extra-terrestrial objects is the 4.6-billion-year wisdom of Solar System events, and by studying them at close quarters using spacecraft we can coerce them into revealing their closely-guarded secrets. This offers us the chance to answer some fundamental questions about our planet and its inhabitants. Exploring comets and asteroids also allows us to shape the story of Earth's future, enabling us to protect our precious planet from the threat of a catastrophic impact from space, and maybe to even recover valuable raw materials from them. This cosmic bounty could be as useful in space as it is on Earth, providing the necessary fuel and supplies for humans as they voyage into deep space to explore more distant locations within the Solar System. Catching Stardust tells the story of these enigmatic celestial objects, revealing how scientists are using them to help understand a crucial time in our history – the birth of the Solar System, and everything contained within it.

The only work to date to collect data gathered during the American and Soviet missions in an accessible and complete reference of current scientific and technical information about the Moon.