Micrometeorites And the Mysteries of Our Origins

by Maurette, Michel

• ISBN13: 9783540258162
• ISBN10: 3540258167
• Format: Hardcover
• Copyright: 2006-05-15
• Publisher: Springer Verlag

Summary

This book relates an attempt to decrypt the still-obscure first billion years of history of the young Earth, during a cataclysmic period during which our planet was heavily bombarded by bodies ranging in size from that of Mars to 0.1 mm sized tiny micrometeorites. It was thus found that micrometeorites played an essential role in the formation of the post-lunar atmosphere. They also provided a surprisingly large diversity of reactions in the organic prebiotic chemistry required for the birth of life on our blue planet. The author presents a wide-ranging review of the type of knowledge required to decrypt this history, which provides extensive background information from astronomy, planetary dynamics, planetology, astrobiology and earth sciences. This book will appeal to both the scientist and the general reader. It will be a source of material for lectures, and possibly new investigations, in these fields. Book jacket.

Table of Contents

Part I Staging the Cosmic Theater
Solar System Bodies and ``Primitiveness''	3	(7)
The Power of Wetherill's Friend, Jupiter	10	(2)
The Earth-Moon System in a Gigantic Cosmic ``Firing'' Range	12	(11)
The Artistry of Radiochronometers	12	(1)
Formation of the Moon by the Last Planetary Embryo Merging the Earth	13	(2)
From Highly Cratered Highlands to Sparsely Cratered Mare on the Moon	15	(3)
Reprocessing of Planetary Materials in Regoliths	18	(3)
Scavenging of Highly Siderophile Elements During Large Impacts	21	(2)
A Microscopic Suspect for the Formation of the Earth's Atmosphere	23	(8)
Beware of Visible and Invisible Shooting Stars	23	(2)
A New ``Star'' in the Cosmic Theater	25	(1)
A Giant Storm of Cometary Shooting Stars?	26	(2)
A Decisive ``Rendez-Vous'' with Antarctic Micrometeorites	28	(3)
Part II ``Primitive'' Extraterrestrial Matter on the Earth
The Space Collector ``Earth''	31	(23)
Dark Stones in Cold and Hot Deserts	31	(3)
Micrometeorites in the Stratosphere and Deep Sea Sediments	34	(5)
Micrometeorites on the Greenland and Antarctic Ice Sheets	39	(12)
Moving to Central Antarctica to Avoid ``Cryogenic'' Weathering	51	(3)
Classification of Meteorites and Micrometeorites	54	(18)
Meteorites	54	(5)
The Hunt for ``Primitiveness''	59	(2)
The ``Deceptively'' Simple Classification of Antarctic Micrometeorites	61	(6)
Beware of Chemical, Mineralogical and Isotopic ``Chaos''	67	(5)
The Major Contribution of Micrometeorites to the Delivery of Hydrous--Carbonaceous Material to the Earth	72	(9)
Part III Formation of the Post-Lunar Earth's Atmosphere
The Inadequacy of Previous Scenarios	81	(5)
Competing Scenarios	81	(1)
Volcanic Outgassing, Accretion of Nebular Gases and Cometary Impacts	82	(1)
A Wrong Neon for the Giant ``wet'' Asteroid?	83	(3)
A Prime Suspect for the Formation of the Atmosphere	86	(7)
Concentrations of Volatiles in Antarctic Micrometeorites	86	(3)
The Micrometeorite ``Purity'' of the Early Earth's Atmosphere	89	(4)
Formation of the Post-lunar Atmosphere	93	(10)
The Invariant Composition of Micrometeorites with Time	94	(2)
An Accretion Formula Born with the Moon	96	(1)
Two Estimates of Φ(t1) from Neon and Nitrogen in the Atmosphere	97	(1)
A Third Independent Estimate of Φ(t1) from the Lunar Impact Record	98	(1)
An Astonishingly Good Fit Between Predictions and Observations	99	(2)
Controversies about Pre-atmospheric Solar Neon and Nitrogen in Micrometeorites	101	(2)
The Mysterious Fate of Early Micrometeoritic Oxygen	103	(4)
Part IV Exobiology with Unmelted Micrometeorites
The Birth of Life on the Early Earth	107	(5)
The Pioneers	108	(2)
Discontinuous ``Bursts'' of Early Life Prior to about 4.2 Gyr Ago?	110	(2)
Microscopic Chondritic Chemical Reactors	112	(13)
A Hydrous-Carbonaceous Chondritic Composition	112	(4)
A Shielding within a Thin Magnetite Shell	116	(2)
A New ``Cosmochromatograph'' and Catalyst, Ferrihydrite	118	(7)
Radiation Reprocessing of Organics by Energetic Ions in Space	125	(10)
Reprocessing of Meteorites and Sporadic Micrometeorites	125	(3)
Pristine-Organics in Shower Micrometeorites: Beware of Analytical Techniques!	128	(7)
Part V Micrometeorite Ashes in Exobiology and Early Climatology
First Hints	135	(1)
Micrometeorite and Minimeteorite Ashes in Prebiotic Chemistry	136	(16)
High Input Rates of SO2 and CO2 to Feed the Early Submarine Hydrothermal System	136	(2)
Kerogen in Shooting Star Chemistry	138	(5)
Dreaming in Sandy Deserts about Persistent Meteor Trains in the Hadean Night Sky	143	(5)
Meteors of cm-size ``Minimeteorites''	148	(2)
Oligoelements in Precambrian Oceans	150	(2)
Micrometeorites in the Post-lunar Greenhouse Effect	152	(7)
The Major Role of the Moon-forming Impact	152	(1)
Early Climatic Effects of the Post-lunar Thermospheric Cocoon	153	(6)
Part VI Micrometeorites in Comparative Planetology
Micrometeoritic Iridium in the Earth's Mantle with the Hartmann's Conjuncture	159	(2)
Micrometeoritic Neon on the Earth	161	(18)
Earlier Suggestions About Micrometeoritic Neon in the Earth's Mantle	161	(2)
A Unique Isotopic Signature of Neon in Antarctic Micrometeorites	163	(3)
The Severe Solar Wind ``Sunburns'' of Micrometeorites	166	(10)
Two ``Relicts'' of Early Micrometeoritic Neon in the Present-Day Atmosphere	176	(1)
A Relict of Micrometeoritic Neon in the Upper Mantle	177	(2)
The Micrometeoritic Purity of the Atmosphere and Early Earth's Processes	179	(4)
A Finely Tuned Occurrence of Early Earth's Processes	179	(1)
The Right Cleaning Impact at the Right Time	180	(3)
Extrapolation of EMMA to the Moon and Mars	183	(16)
The Lunar Iridium Puzzle	183	(6)
EMMA with Spirit and Opportunity on Mars	189	(6)
A Hard Time for EMMA on the Moon and Mars	195	(4)
Part VII Parent Bodies of Micrometeorites and Early Solar System Processes
The ``Hunt'' for Micrometeorites' Parent Bodies	199	(12)
Conventional Views: a Small Abundance of Cometary Micrometeorites	199	(2)
The Inadequacy of Previous Simulations of Atmospheric Entry	201	(2)
Additional Evidence for a Cometary Origin of Micrometeorites	203	(5)
Search for Leonid Cometary Micrometeorites from the Cold	208	(3)
No Consensus About the Early History of the Lunar Impact Flux	211	(21)
The LHBomb in the Debris-Disk Sun	211	(2)
The Fossil Record	213	(3)
Conflicting Conjunctures	216	(3)
Hard Time on the Conjunctures	219	(7)
Regoliths and Old Australian Zircons	226	(6)
Micrometeorites and Early Solar System Processes	232	(7)
A Gigantic Conveyor Belt System of Dust Grains in the Solar Nebula	232	(3)
The Invariant Composition of the Micrometeorite Flux	235	(1)
The Lost Record of High Dust Collision Rates in the Early Debris Disk	236	(3)
Part VIII Challenges Ahead
Relationships with CM-type Chondrites	239	(7)
The Primitive Chondritic Chemical Composition	239	(3)
Anhydrous and Hydrous Silicates	242	(2)
A Broad Distribution of Short Galactic Cosmic Rays Exposure Ages	244	(1)
Major Differences between AMMs and CM Chondrites	245	(1)
The Enigmatic Differences between Stratospheric and Antarctic Micrometeorites	246	(6)
Chemical Composition and Mineralogy of SMMs	246	(2)
Differences with the Cap-Prudhomme AMMs	248	(2)
The Isotopic Puzzle	250	(2)
The World of Hidden Biases: From Collection to Sample Processing	252	(7)
Biases in Greenland and Antarctica	252	(3)
A Preferential ``Skimming'' of Fine-grained Primitive Dust in the Stratosphere?	255	(4)
Stardust Attacks in Bob Laboratory for Space Sciences	259	(7)
Challenges Still to Be Appropriately Addressed	266	(17)
The Opaque Mystery of the Heavy Noble Gases	266	(2)
Japanese Doubts about the Physics of the Giant Moon-forming Impact	268	(1)
The New Hf-W Chronology Invalidates the Timing of EMMA?	269	(1)
The Need for a Strong EUV Heating of the Early Thermosphere Invalidates EMMA?	270	(1)
Light or Heavy Micrometeorite SMOW Water	271	(3)
Nitrogen on Trial	274	(4)
Further Search for a Micrometeorite Contamination of Mars and Venus	278	(5)
Part IX Science and Fiction
Summary	283	(7)
Epilogue: The Birth of ``Micrometeoritics''	290	(8)
References	298	(29)
Index	327