The earth is bombarded both day and night by meteoroids and meteorites. These wayward bodies--small fragments derived from aging comets and the collisions between asteroids--are observed in the Earth’s upper atmosphere as meteors and brilliant fireballs. Written with the amateur astronomer in mind, this book includes step-by-step guidance on visual observation and analyzing data, practical projects that demonstrate how the observer can gather scientifically useful data, and instructions on how to identify and photograph meteor trails.
The genesis of modern searches for observable meteoritic phenomena on the Moon is the paper by Lincoln La Paz in Popular Astronomy magazine in 1938. In it he argued that the absence of observed fashes of meteoritic impacts on the Moon might be interpreted to mean that these bodies are destroyed as luminous meteors in an extremely rarefed lunar atmosphere. The paper suggested the possibility of systematic searches for such possible lunar meteors. With these concepts in mind, I was surprised to note a transient moving bright speck on the Moon on July 10, 1941. It appeared to behave very much as a lunar meteor would – except that the poorly estimated duration would lead to a strongly hyperbolic heliocentric velocity. Thus, the idea of systematic searches for both p- sible lunar meteors and meteoritic impact fashes was born. It was appreciated that much time might need to be expended to achieve any positive results. Systematic searches were carried out by others and myself chiefy in the years 1945–1965 and became a regular program at the newly founded Association of Lunar and Planetary Observers, or ALPO.
Meteors occur when a meteoroid, a speck of dust in space, enters the Earth's atmosphere. The heat generated when this happens causes the surrounding air to glow, resulting in 'shooting stars'. During the most spectacular meteor storms larger particles give rise to fireballs and firework-like displays! Meteors are a delightful observing field - they do not require a telescope, and they can be seen on any clear night of the year, even in bright twilight. It was the sight of a single meteor that inspired David Levy to go into astronomy, and in this book he encourages readers to go outside and witness these wonderful events for themselves. This book is a step-by-step guide to observing meteors and meteor showers. Any necessary science is explained simply and in clearly understandable terms. This is a perfect introduction to observing meteors, and is ideal for both seasoned and budding astronomers.
Dwarf planets (which were formerly called asteroids except for the planet Pluto), and the smaller Solar System bodies still called asteroids today, are making front page news, particularly those that are newly discovered and those that might present a hazard to life on Earth by impacting our planet. In this age of giant telescopes and space probes, these small Solar System bodies have advanced from being tiny points of light to bodies worthy of widespread study. This book describes the dwarf planets and asteroids themselves, their origins, orbits, and composition, and at how amateur astronomers can play a part in their detection, tracking, and imaging. The book is divided into two parts. Part I describes physical properties (including taxonomic types) of dwarf planets and asteroids, how they formed in the early life of the Solar System, and how they evolved to their present positions, groups, and families. It also covers the properties used to define these small Solar System bodies: magnitude, rotation rates (described by their light-curves), and orbital characteristics. Part II opens with a description of the hardware and software an amateur or practical astronomer needs to observe and also to image asteroids. Then numerous observing techniques are covered in depth. Finally, there are lists of relevant amateur and professional organizations and how to submit your own observations to them.
In this era of high-tech instruments, meteor observing is the one facet of astr- omy that needs nothing more than your naked eye. Meteors can be easily seen without the aid of cameras, binoculars, or telescopes. Just ? nd a comfortable chair and lie back and watch for the surprises that await high above you. It is a great way to involve the family in science where everyone is active at the same time, not wa- ing to take turns at the eyepiece. The kids especially enjoy the hunt for “shooting stars,” oohing and ahing at each streak of light that crosses the sky. While gazing upwards, it is also a great way to get more familiar with the sky by learning the constellations and seeing if you can see the warrior among the stars of Orion or the scorpion among the stars of Scorpius. Until just recently, one could simply go outside and watch for meteors from his or her yard. Unfortunately, humankind’s fear of the dark and the widespread use of lighting as advertisement have lit the nighttime scene in urban areas so that only the brightest stars are visible. Serious meteor observing under such conditions is nearly impossible as the more numerous faint meteors are now lost in the glare of urban skies. Today, a serious meteor observing session entails organizing an outing to a country site where the stars can be seen in all their glory and meteors of all magnitudes can be viewed.
This definitive guide provides advanced students and researchers with a detailed yet accessible overview of all of the central topics of meteor science. Leading figures from the field summarise their active research on themes ranging from the physical composition of meteoroids to the most recent optical and radar observations and ongoing theoretical developments. Crucial practical issues are also considered, such as the risk posed by meteoroids - to spacecraft, and on the ground - and future avenues of research are explored. Taking advantage of the latest dynamical models, insights are offered into meteor flight phenomena and the evolution of meteoroid streams and complexes, as well as describing the in-depth laboratory analysis of recovered material. The rapid rate of progress in twenty-first-century research makes this volume essential reading for anyone who wishes to understand how recent developments broaden our understanding of meteors, meteoroids and their origins.
Describes the role that collisions with meteors, comets, and asteroids have played in the history of Earth and other planets in the solar system and examines what is being done to protect Earth from future collisions.
An insider's look at the science of near-Earth comets and asteroids Of all the natural disasters that could befall us, only an Earth impact by a large comet or asteroid has the potential to end civilization in a single blow. Yet these near-Earth objects also offer tantalizing clues to our solar system's origins, and someday could even serve as stepping-stones for space exploration. In this book, Donald Yeomans introduces readers to the science of near-Earth objects—its history, applications, and ongoing quest to find near-Earth objects before they find us. In its course around the sun, the Earth passes through a veritable shooting gallery of millions of nearby comets and asteroids. One such asteroid is thought to have plunged into our planet sixty-five million years ago, triggering a global catastrophe that killed off the dinosaurs. Yeomans provides an up-to-date and accessible guide for understanding the threats posed by near-Earth objects, and also explains how early collisions with them delivered the ingredients that made life on Earth possible. He shows how later impacts spurred evolution, allowing only the most adaptable species to thrive—in fact, we humans may owe our very existence to objects that struck our planet. Yeomans takes readers behind the scenes of today’s efforts to find, track, and study near-Earth objects. He shows how the same comets and asteroids most likely to collide with us could also be mined for precious natural resources like water and oxygen, and used as watering holes and fueling stations for expeditions to Mars and the outermost reaches of our solar system.
"A well-illustrated overview of the science and (literal) impact of these space rocks." -- Science News, on the first edition Leading experts in the field provide a compelling introduction to the space rocks that enter Earth's atmosphere at speeds ranging from 25,000 mph to 160,000 mph. Scientists estimate that about 48.5 tons of meteoritic material falls on the Earth each day. These messengers from space give us a unique insight into the nature of the material that was present when our solar system formed. Many of the specimen meteorites in this second edition were re-photographed to improve quality, and the optical microscopy shots were updated. There is also much new information on discoveries and developments in the study of meteorites, including: Meteorite falls and craters, and new information on ones previously covered Use of weather radar to detect and analyze meteorites, such as the 28,000 mph January 18, 2018, Michigan "fireball" How astrophysicists determine if a meteorite comes from Mars, and information about the Martian meteorites found to date Updated information on the results of the European Space Agency's Rosetta Mission in which a controlled impact was successfully completed into Comet 67P after investigating it with a probe for more than two years. Co-author Sara Russell, who is part of NASA's Mars program, provides the latest news about NASA's Mars programs, including the Mars Rover, which landed in 2016.
"Meteoric phenomena" is the accepted term for the complex of physi cal phenomena that accompany the entry of meteoric bodies into the at mosphere of the earth (or of any planet). "Meteoric bodies" are usually defined as cosmic bodies observed by optical or radar techniques, when they enter the atmosphere. The limiting sensitivity of present-day radar equipment makes it possible to record meteors of up to stellar magnitude +14, while the most brilliant bolides may reach magnitude -19. On a mass 7 7 scale this corresponds approximately to a range of 10- to 10 g. How ever, met~or astronomy is also concerned with larger objects, namely crater-forming meteorites, or objects that cause large-scale destruction when they arrive through the atmosphere (an example is the Tunguska River meteorite). Consideration of the interaction of such objects with 12 the terrestrial atmosphere extends the mass range to 10 g. On the other hand, scientists studying fragmentation processes in meteoric bod 7 ies have to consider particles with masses less than 10- g, and the use of data from meteoric-particle counters on rockets and artificial satel lites, from microcraters on the lunar surface, and from noctilucent clouds 12 lowers the minimum mass to 10- g. Therefore, the mass range of meteoric bodies, or meteoroids, encompasses 24 orders of magnitude. Although recent years have witnessed considerable development in meteor research, both in the Soviet Union and elsewhere, the main mono graphs on meteor physics were published twenty or more years ago.
