Dr Vic Pearson (UK) Every year, thousands of tonnes of dust and rock penetrate the Earth’s atmosphere. The fiery passage of these objects produces the familiar ‘shooting star’ phenomenon, known as meteors. Much is destroyed during this descent, but some material is delivered to the Earth’s surface, either as meteorites or micrometeorites (the latter being typically less than 1mm). However, only 1% of the surviving material is large enough for identification and recovery, making meteorites and micrometeorites much sought after, both scientifically and commercially. Fig. 1. Meteors, or shooting stars, are a regular sight in our skies. Not all survive atmospheric entry but produce spectacular fireballs. (Image courtesy of A. Danielson.) Naturally, bombardment by extraterrestrial materials has been ongoing throughout Earth’s history. The early Solar System would have been a turbulent time and the young Earth was subject to much greater amounts of extraterrestrial infall than today. Our geological record contains many impact craters, and fossilised meteorites have been found in Ordovician sediments in Sweden (Schmitz et al., 2001), thought to be the result of the catastrophic break-up of an asteroid 470 million years ago. Today, it is accepted that the majority of meteorites are fragments of asteroids broken off during collisions with other extraterrestrial objects, perturbed from their orbits by the gravitational effects of Jupiter. The origins of micrometeorites are less well constrained and evidence abounds for both cometary and asteroidal origins. Types of meteorites Meteorites are generally classified as either falls or finds. Falls are those that are … Read More
Dr Kendal Martyn Meteorites have long held fascination for me – that is, they aren’t from this planet. Added “glamour” has come from recent suggestions that at least one meteorite impact on earth could be responsible for mass-extinction events, the largest “smoking gun” in evolutionary selection. Also, meteorites are the … Read More
This is a nice little guide for the non-specialist collector of all things that go bump from above (and the effects they have on the rocks they impact). As is clear from the title, the book covers three wide categories: meteorites, tektites and impactites.
David Bryant (UK) Perhaps unsurprisingly (as a professional dealer in space rocks), I find all meteorites equally fascinating and, in their own way, aesthetically appealing. However, I have to admit, the meteorites known as the Pallasites, with their beautiful structure of olivine fragments suspended in a nickel-iron matrix, are probably … Read More
Jon Larsen (Norway) Is it possible to find micrometeorites in populated areas? The question has been raised for nearly a century and, despite numerous attempts to find them, the answer up to this day has been a very short “no”. Meanwhile, our knowledge about these amazing stones has gradually increased. … Read More
Chelsea Leu (USA) A new study, published by University of Chicago researchers challenges, the notion that the force of an exploding star forced the formation of the solar system. In this study, published online in Earth and Planetary Science Letters in November 2012, authors Haolan Tang and Nicolas Dauphas found … Read More
It is a wonderful state of affairs that we can not only now write detailed books about planetary geology and geomorphology of the bodies in the solar system, but we can also illustrate them with wonderful photographs.
Dr Steve Koppes (USA) Hikers visiting the Kilauea Iki crater in Hawaii today walk along a mostly flat surface of sparsely vegetated basalt. It looks like parking lot asphalt, but, in November and December 1959, it emitted the orange glow of newly erupted lava. Now, a precision analysis of lava … Read More
It appears that I was naive to assume the Tunguska explosion of 1908 had been adequately explained. It was a meteorite or, more probably, a comet that exploded above a remote area of Siberia. Wrong! This fascinating book shows that we still await an adequate scientific explanation and the jury is still out on what precisely the object was.