Impact Craters caused by Asteroids
Barringer's Meteor Crater
Wolfe Creek Crater
SpaceWeather Information & Resources
Getting Ready for the Next Big Solar Storm
What is Heliophysics | NASA Living With a Star | Heliophysics Summer School
NOAA Space Weather Prediction Center | The Australian Space Weather Agency
Space Weather Radio | ESA Space Environment Information System
Realtime Space Weather Photo Gallery
Realtime Comet Photo Gallery
As of Today
according to Near-Earth asteroid monitoring groups
the ever-increasing number of
KNOWN Potentially Hazardous Asteroids
in Earth-Crossing orbits
are listed here
Why Does This Number Go Up, Then Sometimes Go Down?
Book an Educational Visit to the UK SpaceGuard Centre
The National Near Earth Objects Information Centre
is located in Knighton, Powys, LD7 1LW, Wales, United Kingdom
It is open for Public Tours (suitable for ages 9+), and also for
School Tours (suitable for primary & secondary schools)
They are are easily accessible - See Map and directions
Impact Craters throughout the Solar System
FULL LIST OF KNOWN
FULL LIST OF KNOWN
FULL LIST OF KNOWN
FULL LIST OF KNOWN
Links to other sites
Do the building blocks of life travel throughout the universe on comets and on asteroids?
Below is a small selection of books suggesting that it probably does
"An excellent introduction into the newly emerging and exciting field of astrobiology. An essential, enjoyable and highly readable insight into life in its cosmic context."
"Planets and Life: The Emerging Science of Astrobiology"
"Astrobiology involves the study of the origin and history of life on Earth, planets and moons where life may have arisen, and the search for extraterrestrial life. It combines the sciences of biology, chemistry, palaeontology, geology, planetary physics and astronomy. This textbook brings together world experts in each of these disciplines to provide the most comprehensive coverage of the field currently available."
"This up-to-date resource is based on lectures developed by experts in the relevant fields and carefully edited by the leading astrobiologists within the European community. Aimed at graduate students in physics, astronomy and biology and their lecturers, the text begins with a general introduction to astrobiology, followed by sections on basic prebiotic chemistry, extremophiles, and habitability in our solar system and beyond."
"The dynamic field of astrochemistry brings together ideas of physics, astrophysics, biology and chemistry to the study of molecules between stars, around stars and on planets. Astrochemistry: from Astronomy to Astrobiology provides a clear and concise introduction to this rapidly evolving multidisciplinary subject. Starting with the Molecular Universe, the text covers the formation of the elements, simple models of stars and their classification. It then moves on to draw on the theme of the Origins of Life to study interstellar chemistry, meteorite and comet chemistry as well as the chemistry of planets."
"Fitness of the Cosmos for Life: Biochemistry and Fine-Tuning"
"This highly interdisciplinary book highlights many of the ways in which chemistry plays a crucial role in making life an evolutionary possibility in the universe. Cosmologists and particle physicists have often explored how the observed laws and constants of nature lie within a narrow range that allows complexity and life to evolve and adapt. Here, these anthropic considerations are diversified in a host of new ways to identify the most sensitive features of biochemistry and astrobiology. Celebrating the classic 1913 work of Lawrence J. Henderson, The Fitness of the Environment for Life, this book looks at the delicate balance between chemistry and the ambient conditions in the universe that permit complex chemical networks and structures to exist."
"Astrobiology: A Multidisciplinary Approach is the most comprehensive textbook available for emerging upper-level courses in astrobiology. Internationally renowned authority Jonathan Lunine gives students with a variety of backgrounds a solid foundation in the essential concepts of physics, chemistry, biology, and other relevant sciences to help them achieve a well-rounded understanding of the fascinating study of the origin of life, planetary evolution, and life in the cosmos."
"Asteroids and comets: Every year, millions of these 'stray bullets' streak through the skies, and tons of small meteorites strike our planet! Some 65 million years ago, dinosaurs were wiped off the face of the earth - in what many believe was the aftermath of a massive cosmic collision. Could something like this happen again? Scientists believe that the impact of an asteroid only a mile wide would be globally catastrophic."
"Comet science is a field that has seen tremendous advances in recent years, far surpassing the knowledge reflected in the original Comets volume published as part of the Space Science Series in 1982. This new volume, with more than seventy contributing authors, contains the most extensive collection of knowledge yet assembled in the field. It will enable scientists involved in their study to make connections across disciplinary boundaries and will set the stage for discovery and new understanding in the coming years."
"Comet Hale-Bopp defines a milestone event for cometary science: it is the first "really big" comet observed with modern equipment on the ground and from space and due to that; it is considered the new reference object in cometary sciences. At the beginning of a new era in spacecraft exploration of comets and five years after Hale-Bopp's perihelion passage these proceedings of invited and contributed papers for IAU Colloquium 186 "Cometary Science after Hale-Bopp" review the state-of-the-art knowledge on comets, the icy, dusty and most primordial left-overs of the formation disk of our own solar system."
"Around 700 BC an Assyrian scribe in the Royal Place at Nineveh made a copy of one of the most important documents in the royal collection. Two and a half thousand years later it was found by Henry Layard in the remains of the palace library. It ended up in the British Museum's cuneiform clay tablet collection as catalogue No. K8538 (also called 'the Planisphere'), where it has puzzled scholars for over a hundred and fifty years.
In this monograph Bond and Hempsell provide the first comprehensive translation of the tablet, showing it to be a contemporary Sumerian observation of an Aten asteroid over a kilometre in diameter that impacted Kofels in Austria in the early morning of 29th June 3123 BC."
For many years academics in the historical sciences were content in their belief that terrestrial impacts by solid bodies from space was something that only happened in the very early history of our planet, whilst the average person had never heard the word 'asteroid'. Then in 1980 the Nobel prizewinning physicist, Luis Alvarez, and his colleagues published their famous paper in "Science" which argued that a cosmic impact had led to the extinction of the dinosaurs. He showed that large amounts of the element iridium present in geological layers dating from about 65 million years BP had a cosmic origin, and proposed a radical theory that it was a massive 'asteroid impact' 65 million years ago which finally wiped out the dinosaurs.
Over the following decade interest began to rise in the idea of 'terrestrial impacts', and by 1990 most scientists at least accepted that the craters on our Moon were caused by impacts of cometary debris and asteroids of varying sizes, and not the volcanoes they had previously thought responsible.
As space exploration continued, the images sent back to Earth, especially by the Voyager spacecraft, allowed astronomers to build a picture of the sort of dynamic solar system first suggested by Victor Clube and Bill Napier in their groundbreaking books "Cosmic Serpent", published 1982, and developed further in "Cosmic Winter" published 1990.
This was a new model of the solar system. One where regular influxes of comets from the various areas of space transitted by our solar system in its orbit through the galaxy suggested inevitable, and multiple, collisions with all the planetary bodies and their respective moons. Technologicl advances in space imaging have since shown a multitude of impact craters on all the inner planets and their moons. But some 12 years after the theories about the cosmic impact which led to the extinction of the dinosaurs were first proposed, the possibility of cometary bombardments still seemed something that belonged way back in the very early history of our solar system - even to most scientists.
It was on March 24 1993 that astronomers, husband and wife team Carolyn S. and Eugene M. Shoemaker, and David H. Levy, discovered a new comet in our solar system. Observations over the next few months determined that the comet was, at least temporarily, in orbit around Jupiter, and that on July 7 1992 the tidal forces of the largest planet in our solar system had caused the comet, by then named P/Shoemaker-Levy 9, to disintegrate. Over the next year or so astronomers on Earth observed the fragments proceeding around the Sun and heading back on a collision course directly for Jupiter. From July 16th to 22nd 1994 they watched in awe as the 21 fragments bombarded the visible surface of Jupiter causing 'fireballs' 50 times the size of Earth and leaving huge scars on Jupiter's southern hemisphere.
This was a wake-up call even for those who understood what was going on, and resulted in more funding being requested by astronomers to research the frequency of impacts throughout the solar system, but also to search for any evidence of past impacts on Earth. Following this event, there was an abrupt realisation by astonomers that if it can happen to Jupiter now, it can also happen to Earth in the future, and the search began in earnest to identify the exact orbital paths of all Earth-orbit-crossing celestial objects.
If anyone is in any doubt as to exactly how dangerous a place our planet occupies in the solar system they should simply look at our Moon. There for all to see with the naked eye, and in even greater detail using a pair of good binoculars or a small telescope, are impact craters galore. There doesn't appear to be one square mile of the lunar surface that is not pockmarked with impact craters, and while some are undoubtedly very ancient they also contain within their crater rims a multitude of newer craters from much more recent impacts. The reason why there are so many visible craters on the Moon from ancient impacts was summed up well by astronomer, Duncan Steel, in his 1995 book, "Rogue Asteroids and Doomsday Comets":
"Craters are relatively swiftly eroded on Earth by rain, snow, and wind, whereas on the Moon they remain for eons until a new projectile happens to erase the scar left by some cousin countless millennia before."
So this explains, partially, why there are so few visible craters on Earth. But raises the obvious question as to why we can't see more given that, if our Moon is so cratered, surely our planet must be an even bigger target in the same area of the solar system? The answer is at once simple and also very complex. Firstly, there is approximately 71% of the surface area of the Earth covered with oceans - leaving just 29% dry land surface area. This gives a 3 to 1 chance that any incoming impactor will, if it doesn't explode a few miles up like whatever happenned at Tunguska in 1908, impact one of the oceans and leave no easily visible trace.
Secondly, any crater on dry land would be at the mercy of the elements, and should there have been collisions with cometary debris, or asteroids, in the Amazon Basin, say, then vegetation would without doubt obscure them in a very short time indeed. But these are not the only factors, as Duncan Steel explained:
"The length of time that a crater will survive depends not only on the regions in which it is formed, but also on it's size. Obviously a crater 50 kilometers across will last longer than a comparatibe pipsqueak just 100 meters in diameter. For example, in Australia there are 19 known craters - probably there are dozens more awaiting discovery - and of those, four are less than about 6,000 years old. Those are the four smallest however, all being less than 200 meters in diameter."
At the time that Duncan Steel was writing "Rogue Asteroids and Doomsday Comets" in 1994/1995, there were then only about 140 known terrestrial impact craters. But in the years since then, spurred on by a new-found sense of urgency following the events on Jupiter in July 1994, the search picked up steam, and many more have been discovered.
The current tally is just under 1000, and there is an interactive map of all the terrestrial impact craters accessible at the University of Arizona website. This is an excellent resource for anyone wishing to see just how many have so far been discovered on just the 29% of the surface area of our planet that is currenly dry land.
Another good resource for information about terrestrial impact craters which also has an interactive map is accessible at the University of New Brunswick Canadian website. The first paragraph or so of their introduction to the subject is worth quoting from here, as it puts the dynamic history of the solar system into a proper perspective:
"Until recently, impacts by extraterrestrial bodies were regarded as an interesting but, perhaps, not an important phenomenon in the spectrum of geological process affecting the Earth. Our concept of the importance of impact processes, however, has been changed radically through planetary exploration, which has shown that virtually all planetary surfaces are cratered from the impact of interplanetary bodies. It is now clear from planetary bodies that have retained portions of their earliest surfaces that impact was a dominant geologic process throughout the early solar system.
For example, the oldest lunar surfaces are literally saturated with impact craters, produced by an intense bombardment which lasted from 4.6 to approximately 3.9 billion years ago, at least a 100 times higher than the present impact flux. The Earth, as part of the solar system, experienced the same bombardment as the other planetary bodies."
On this page we have tried to compile a photographic collection of impact craters on Earth to demonstrate just how many there actually are. Asteroids vary in their composition. Some are composed purely of stoney materials, some are composed of nickel & iron, while others have varying combinations of both. It should be understood that many of the asteroids which are made up of stoney materials do not survive the journey through our atmosphere. They explode in the upper atmosphere as the white-hot matter caused by friction upon entry hits the freezing cold air.
This has happened as recently as 1908 over the Tunguska region of Siberia, where the 'air-burst' caused an explosion the equivalent of many hundreds of nuclear bombs. Because the asteroid, or fragment of cometary debris, detonated in the upper atmosphere there was no impact crater to show what had happened, but many thousands of square miles of forest lands were completely flattened all around the detonation area.
The Tunguska airburst, Siberia - June 1908
How many times has this happened before? And how soon will it be before an something like this happens again? ...
"10 Greatest Major-Impact Craters on Earth"
Imagine staring into the sky and seeing a tiny yellow dot, gradually getting closer. That dot doubles in size every second, until it slowly darkens the sky. You realize that this dot is actually the size of New York City and is screeching through the atmosphere faster than the speed of sound, coming right for you. This massive object will cause tsunamis, earthquakes and obliterate natural daylight for years ... oh ... and it will kill you.
Similar asteroid impacts have and will happen on numerous occasions in our earth?s history. Today we?ll show you the biggest impact craters by diameter.
Over 100 Years Since The Tunguska Event
It has now been 100 years since the events of June 30, 1908, when a bolide of some description exploded over the Tunguska River region of Siberia. A conference to mark the anniversary took place in Moscow, Russia in 2008.
"Tunguska: 100 years of wondering"
One hundred years ago, an explosion bigger than an atomic bomb blasted Tunguska, Siberia. We still don't know what caused it, but there are plenty of theories!
Early on the morning of June 30, 1908, a massive explosion rocked the Siberian wilderness flattening more than 2,000 square kilometres of forest.
Villagers 100 kilometres away from the Podkamennaya Tunguska river basin reported seeing a fireball in the sky, feeling intense heat, hearing loud thumps and being thrown off their feet.
'The split in the sky grew larger, and the entire Northern side was covered with fire. At that moment I became so hot that I couldn't bear it, as if my shirt was on fire; from the northern side, where the fire was, came strong heat.'
'I wanted to tear off my shirt and throw it down, but then the sky shut closed, and a strong thump sounded, and I was thrown a few yards', reported one villager.
The explosion lit up the sky as far away as London for several days.
Nearly two decades later, the first expedition into the area led by Russian meteorite specialist Leonid Kulik found a region of scorched trees 50 km in diameter, but no crater.
It's now believed that the Tunguska event ? as it's now known ? was hundreds of times more powerful than the atomic bomb dropped on Hiroshima
Tunguska has long fascinated scientists, enthusiasts and sci-fi fans. Over the years, the mystery of the event has prompted a number of theories with varying degrees of scientific plausibility. These have ranged from a meteorite to the crash of an alien spacecraft; an explosion of methane or the result of Nikola Tesla's experiments with electricity near New York." [Full Story]
November 25 2014, NASA Earth Observatory, Earth Orbit
October 27 2014, ESA News, France
September 29 2014, ESA News, France
September 19 2014, ESA News, France
August 18 2014, ESA News, France
July 21 2014, ESA News, France
August 2014, Geology Magazine, USA
July 10 2014, ESA News, France
May 26 2014, ESA News, France
February 10 2014, ESA News, France
January 02 2014, Sky & Telescope, USA
December 17, 2013, NASA LROC, Lunar Orbit
December 09, 2013, NASA Earth Observatory, Earth Orbit
November 29, 2013, ESA Space in Images, Earth Orbit
September 04, 2013, ESA Mars Express News, Mars Orbit
March 04, 2013, ISS, Earth Orbit
[ A good high resolution image of this newly discovered crater in NW Australia can be accessed HERE - JM. ]
"Russia?s Urals region has been rocked by a meteorite explosion in the stratosphere. The impact wave damaged several buildings, and blew out thousands of windows amid frigid winter weather. Hundreds are seeking medical attention for minor injuries, [TV channel Russia Today (RT.com) has reported].
Russian Meteorite Explosion Video Footage
[Later this evening, February 15 2013,
Asteroid 2012 DA14, with an estimated diameter of 65 metres, is due to fly past Earth with a staggeringly small miss distance of less than one tenth of the distance between Earth and the Moon.
RUSSIAN ASTEROID IMPACT UPDATE February 18 2013: It is now known that some 1200 people were injured as a result of what NASA says was an asteroid: 'about 17 meters in diameter and weighed approximately 10,000 metric tons'.
January 21, 2013, ABC Science News, Australia
October 18, 2012, SpaceWeather.com / SETI, USA
September 06, 2012, ESA News, France
August 02, 2012, ESA News, France
June 24, 2012, NASA Earth Observatory, Earth Orbit
May 07, 2012, NASA Earth Observatory, Earth Orbit
April 23, 2012, ABC Science News, Australia
February 09, 2012, Discovery News, USA
With a weight that rivals a baby elephant, a meteorite that fell from space some 30,000 years ago is likely Britain's largest space rock. And after much sleuthing, researchers think they know where it came from and how it survived so long without weathering away.
The giant rock, spanning about 1.6 feet (0.5 meters) across and weighing 205 pounds (93 kilograms), was likely discovered by an archaeologist about 200 years ago at a burial site created by the Druids (an ancient Celtic priesthood) near Stonehenge, according to said Colin Pillinger, a professor of planetary sciences at the Open University.
Pillinger curated the exhibition "Objects in Space," which opened Feb. 9 and is the first time the public will get a chance to see the meteorite. The exhibition will explore not only the mystery that surrounds the origins of the giant meteorite, but also the history and our fascination with space rocks.
'Britain was under an ice age for 20,000 years', Pillinger told LiveScience, explaining the climate would have protected the rock from weathering." [Full Story]
Below are some images of the larger known asteroids
"Several spacecraft have orbited or landed on asteroids and sent pictures of these bodies back to Earth. The NEAR Shoemaker mission, launched in 1996, was the first spacecraft to land on an asteroid, touching down on Eros on February 12, 2001."
Asteroid 253 Mathilde
On June 27, the NEAR (for Near Earth Asteroid Rendezvous) spacecraft, traveling some 36,000 kilometers per hour, streaked past an asteroid named Mathilde far beyond the orbit of Mars. It was just a brief encounter along a long journey to a different asteroid, Eros.
"Liquid water, carbon-based molecules and a relatively stable environment are critical elements for life. Comets and asteroids can bring water and the chemicals on which life is based, but can also bring widespread destruction. If future impacts are inevitable, what should we do?"
Books About Asteroids, Comets, Meteor Storms, Impact Craters & Ancient Cosmic Catastrophes
"The 2300 BC Event - Vol. 1:
"The 2300 BC Event takes a new look at an old puzzle: what happened at this date to cause the advanced societies on the Earth to simultaneously collapse?
Civilizations in Anatolia and Greece, through Egypt and the Middle East, and eastward to India and Central Asia were at their height. The collapse of these civilizations due to earthquakes and climatic changes has been mirrored by similar interruptions on all continents, in the Arctic, and extending into the Pacific.
The discontinuities have long puzzled archaeologists and historians. New religions and accompanying mythologies appeared at this time in all cultural regions describing bombardment and flooding from the skies.
Strangely, the dominant aspect of the mythologies, however, is the observation and worship of a ring appearing to surround the Earth, oriented to the two Ursa (Bear) constellations."
"The 2300 BC Event Vol. 2:
"Some time around 2300 BC the Eath encountered a dense clustering of space debris, the early Southern & Northern Taurid meteoroid stream. The result was an intense fall of meteoroids, some of them sufficiently large to cause surface destruction.
Simultaneous with the meteoroid fall was a huge downpouring of water which caused flash flooding. Extensive destruction and loss of life resulted. An astonishing aspect of the event was the formation of a ring surrounding the Earth, reflecting sunlight during the day, hiding some stars at night, and moving around the sky through a 24-hour period.
Following the 'main event', there were crustal movements which shifted the location of water sources, and caused earthquakes which destroyed settlements. Abrupt severe climate changes occurred."
"The 2300 BC Event Vol. 3:
"The Northern/Southern Taurid meteoroid stream is identified as the specific meteoroid stream that the Earth encountered at 2300 BC.
The Earth's encounter with a dense cluster of large objects would produce atmospheric phenomena very different from the pleasant and interesting night displays of meteor trails that are within our own experience.
The rain of objects would have generated extraordinary visual and auditory effects combined with ground vibrations; and under extreme conditions would bring about severe surface destruction and loss of life.
The overall event was associated by the people with powerful deities and formed the basis for major religions. The mythologies and traditions are, in large part, the residues of those religions."
Research in the field of neo-catastrophism and impact cratering has quickened its pace since the early 1980s. Scholars such as Victor Clube, Bill Napier, Mark Bailey, Sir Fred Hoyle and Duncan Steel claim that a more 'active' sky might have caused major cultural changes of Bronze Age civilizations, belief systems and religious rituals."
"Around 700 BC an Assyrian scribe in the Royal Place at Nineveh made a copy of one of the most important documents in the royal collection. Two and a half thousand years later it was found by Henry Layard in the remains of the palace library. It ended up in the British Museum's cuneiform clay tablet collection as catalogue No. K8538 (also called "the Planisphere"), where it has puzzled scholars for over a hundred and fifty years. In this monograph Bond and Hempsell provide the first comprehensive translation of the tablet, showing it to be a contemporary Sumerian observation of an Aten asteroid over a kilometre in diameter that impacted Kofels in Austria in the early morning of 29th June 3123 BC."
"This volume synthesizes 16 years of geological and geophysical studies which document an 85-km-wide impact crater buried 500 m beneath Chesapeake Bay in south eastern Virginia, USA. The authors integrate extensive seismic reflection profiling and deep core drilling to analyze the structure, morphology, gravimetrics, sedimentology, petrology, geochemistry, and paleontology of this submarine structure. Of special interest are a detailed comparison with other terrestrial and extraterrestrial craters, as well as a conceptual model and computer simulation of the impact. The extensive illustrations encompass more than 150 line drawings and core photographs. An accompanying CD-ROM includes selected seismic profiles, scaled cross sections, detailed maps, and downhole geophysical logs."
"Describes a search for geological evidence of meteorite impact structures in Britain. The statistics of impact structures indicate that Britain should have Phanerozoic impact structures up to tens of kilometres in diameter. A constant theme is the importance of atmospheric break-up of small asteroids and comets. These fragmenting bodies produce anomalously shallow craters with low rims and central peaks; three British structures of this type are identified. Analysis of fireball statistics implies that damaging fireball explosions occur over the British Isles on a time-scale of decades. On a time-scale of millennia, however, more damage is done by Atlantic impact tsunami."
"Mackenzie prefaces his absorbing account of the new "giant impact" theory of the moon's origin with the fascinating story of humanity's long relationship with Earth's only natural satellite. Evidence of that relationship begins with what is very probably a lunar calendar among the famous Lascaux cave paintings, and continues in early civilizations' timekeeping uses of the moon and classical Greek ideas about the moon's composition. In the fifth century B.C.E., Anaxagoras correctly realized that the moon was made of rock. Later, Aristotle didn't agree, and his view held sway for centuries."
"This volume is the 8th in a series of impact books resulting from the activities of the scientific program "Response of the Earth System to Impact Processes" (IMPACT), by the European Science Foundation. The book resulted from an international meeting at Mora, Sweden, which was held as part of the IMPACT program. The papers cover various structural geologic, geochemical, and geophysical topics on research of asteroid impact structures on Earth and Mars."
"In recent years, meteorites have caught the imagination of scientist and collector alike. An army of people are now actively searching for them in the hot and cold deserts of Earth. Fascinating extraterrestrial rocks in meteorites are our only contact with materials from beyond the Earth-Moon system."
"The Celtic myths, involving heroic warriors such as Finn and CuChulinn, can be read as simple primitive stories, but closer examination reveals strange descriptions and relationships.
The authors of this ground-breaking book argue that all the principal characters are aspects of the one Celtic sky god, Lugh, who was a comet. Against the background of a comet scenario this re-interpretation of about ten key Celtic myths shows how many of the descriptions in the myths fit the appearance of comets.
The fact that these comets on occasions produced abrupt environmental changes, that can be traced in the tree-ring and ice-core chronologies, pins the stories to a central reality. With a novel twist this original book confirms the widespread belief that these stories must contain 'a core of truth'."
"Could both Stonehenge and the pyramids of Egypt have been constructed to observe and commemorate a period of phenomenal meteor storms and asteroid detonations produced by a burst of activity in the Taurid Complex 4,500 to 5,000 years ago? Author Duncan Steel examines the evidence indicating rogue asteroids and doomsday comets may have been behind these and other ancient phenomena."
"The End of the Dinosaurs gives a detailed account of the great mass extinction that rocked the Earth 65 million years ago, and focuses on the discovery of the culprit: the Chicxulub impact crater in Mexico. It recounts the birth of the cosmic hypothesis, the controversy that preceded its acceptance, the search for the crater, its discovery and ongoing exploration, and the effect of the giant impact on the biosphere. Other mass extinctions in the fossil record are reviewed, as is the threat of asteroids and comets to our planet today. The account of the impact and its aftermath is suitable for general readers. The description of the crater geology is in enough detail to interest students of the earth sciences. A detailed index and bibliography are included."
"During its five billion year history, Earth has been hit countless times by asteroids and meteorites. Over 150 crater-producing events have been identified, and this book describes all 139 sites worldwide at which evidence of the impacts can be seen. They range in age from recent craters formed this century to the highly eroded billion-year old ancient craters. Some are spectacular to visit, such as the Barringer Crater in Arizona, the ring-shaped mountains of Gosses Bluff, Australia, and the huge crater at Ries in Germany.
For each site there is a summary table giving location, size, age and present condition. Maps are included where necessary. The author has visited many of the sites and his photographs enrich this thorough survey. Meteorite craters are fascinating to visit, so the descriptions include guidance about access and suggested itineraries for the large structures."
"On the morning of June 30, 1908, a fireball cascaded down the Siberian sky and exploded with 2000 times the force of the nuclear blast that devastated Hiroshima, Japan. Weighing some 100,000 metric tons, the cosmic missile cut into the atmosphere and shattered in a rapid series of bursts, felling trees and incinerating an area of 2150 square miles - now known as the Tunguska 'event'.
In the spring of 1992, Roy Gallant was invited by the Siberian branch of the National Academy of Sciences to take part in the annual Tunguska Expedition, to investigate this largest meteorite explosion in human history."
"In the early years of the twentieth century, an enormous bowl-shaped hole in the high plains of northern Arizona was investigated by a mining engineer and his associates. The hole was almost three quarters of a mile wide-a little over one kilometer¹-and it penetrated thick layers of subsurface rock.
The investigators concluded that it was created thousands of years ago when a mass of meteoritic iron struck the earth, and they produced extensive evidence in support of their claim."
"Norton (astronomy, Central Oregon Community College) tells the story of meteorites and our attempts to read their history. Topics include the development of the interdisciplinary science of meteoritics, asteroids, current classifications of meteorites, and the impact of the comet Shoemaker-Levy on Jupiter in 1994.
"A straightforward, thorough look at all aspects of meteors and meteorites, including how and where meteors originate, when and where to watch for them, and how to classify, collect, and preserve meteorites. Meteor showers, interesting meteorite craters, and tektites are all discussed in detail. Also contains a comprehensive listing of meteorite organisations, dealers, museums, and references."
please take a look at our Comet & Asteroid Impact Book Pages for a selection of books about
the past and present threat to our planet from comets and asteroids, dust-loading
of our stratosphere by cometary debris, and the proposals for an
international SpaceGuard effort and Planetary Defence
please take a look at our Ancient Mysteries Bookshoppe for a wide selection of books
that challenge orthodox views of prehistory on every continent
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