When the Earth Had Two Moons

When the Earth Had Two Moons[Ebook] ➠ When the Earth Had Two Moons By Erik Asphaug – Heartforum.co.uk An astonishing exploration of planet formation and the origins of life by one of the world’s most innovative planetary geologistsIn 1959 the Soviet probe Luna 3 took the first photos of the far side An astonishing exploration of Earth Had Kindle × planet formation and the origins of life by one of the world’s most innovative planetary geologistsIn the Soviet probe Luna took the first photos of the far side of the moon Even in their poor resolution the images stunned scientists the far side is an enormous mountainous expanse not the vast lava plains seen from Earth Subseuent missions have confirmed this in much greater detailHow could this be and what might it tell us about When the ePUB × our own place in the universe As it turns out uite a lotFourteen billion years ago the universe exploded into being creating galaxies and stars Planets formed out of the leftover dust and gas that coalesced into larger and larger bodies orbiting around each star In a sort of heavenly survival of the fittest planetary bodies smashed into each other until solar systems emerged Curiously instead of being relatively similar in terms of composition the planets in our solar system and the the Earth Had eBook ✓ comets asteroids satellites and rings are bewitchingly distinct So too the halves of our moonIn When the Earth Had Two Moons esteemed planetary geologist Erik Asphaug takes us on an exhilarating tour through the farthest reaches of time and our galaxy to find out why Beautifully written and provocatively argued When the Earth Had Two Moons is not only a mind blowing astronomical tour but a profound inuiry into the nature of life here—and billions of miles from home.


When the Earth Had Two Moons Epub ↠ When the  ePUB
  • Audiobook
  • When the Earth Had Two Moons
  • Erik Asphaug
  • 09 October 2016
  • 9780062895080

10 thoughts on “When the Earth Had Two Moons

  1. Sumit RK says:

    An amazing exploration of planet formation and the origins of lifeIn When the Earth Had Two Moons planetary geologist Erik Asphaug takes us on an exciting tour of our galaxy detailing strangest miracles in space and an examination into the nature of life Asphaug explores a variety of planetary forms—including comets asteroids moons and the sun—as he explores the complex and deeply galaxy and beyond Combining his own research with scientific discoveries He discusses the origin of life our own understanding of the universe on the history and current knowledge of the planets familiar and unfamiliar moons and unattached bodies in between He has added several other interesting titbits like Pluto’s status as a planet or how exploring Jupiter will feel like As a geologist he also devotes entire chapters to extraterrestrial topography plate tectonics and our pursuit of liuid water throughout the galaxy As an academic and as a Professor of Planetary Science at various universities Asphaug brings his rich experience and amazing insights into writing this book Asphaug opts for concise explanations over the relatively abstract astrophysics Having said that the overly technical language is likely to irritate general readers Let’s face it astrology and advanced physics are not easy topics to grasp for lay readers Hence many readers could find sections of the book a bit too complex to understandOverall the book is an exciting tour of the galaxy exploring many topics at once Though a bit technical at times it’s still an interesting and entertaining guide to our unknown galaxy Three and a half stars Many thanks to the publishers HarperCollins the author Erik Asphaug and Edelweiss for the ARC

  2. Peter Tillman says:

    An amazing introduction to modern planetary science by a working specialist in just that This is my favorite sort of science book by a scientist who’s enthusiastic about his field Prof Aspaug writes really well and his book is full of good surprises I thought I was fairly well up to date in planetary science but I learned a lot from his book Highly and enthusiastically recommendedThe author worked hard to make his book accessible to non technical readers but you will get out of it if you have a general background in the topic Some of his best stuff is in the notes so be sure to follow those about stuff that you find particularly interesting He’s the sort of guy I would love to meet and the sort of professor you would have loved to have in schoolTakeaways from my notes there are a LOT of unsolved mysteries in the evolution of our solar system — and even unknowns about exoplanets Here’s one still being worked out The TRAPPIST 1 exoplanet system its star is just slightly larger than our Jupiter but 84 times massive 18 the mass of our sun — and it’s compressed to 10x the density of iron Details is a dim red dwarf star expected to burn for trillions of years or 100 times as long as the current age of our universe Red dwarves are common and may prove to be the best bet for finding extrasolar life TRAPPIST 1 alone has at least 3 planets in its habitable zone Asphaug is a cheerleader for planetary exploration it’s cheap fun and inspirational Sure beats warfare as a way for nations to strut their stuff Which they always have back to the Greeks and before and always will His go to example is the US moon landing missions in the 1960s which used repurposed war rockets As did the rest of the US space program and the Russians and now the Chinese All these programs have had he says practical spin offs which have paid back their costs and promoted international cooperation The current ecological crises are a nudge that cooperative scientific research would be a really good idea

  3. Carlos says:

    This is a very informative book although a bit dry There is a lot of science but also a lot of conjecture which is precisely what the author intended when writing this book he says that the we explore the unknown space the conjectures we will have to take until we can fix everything in one theorem The uestions we ask and the we realize how little we know about how our own moon was built and how our sun burns and wether this same circumstances could be replicated in another solar system the we will resume exploring space

  4. Grumpus says:

    The grumpus23 23 word commentaryIf you have an interest this is a good presentation of the randomness of the cosmos and how it all came to be

  5. Elise says:

    I enjoyed this well written discussion of planetary development The author built his thesis from the ground up literally starting with what we know about earth and lunar geology before expanding into the solar system and beyondHe covers recent exoplanet discoveries linking it back to the many theories about the formation of our own solar systemA wry sense of humor is in evidence along with anecdotes that bring the science to life The footnotes are especially interesting some of them providing web links to astrophysical articles and images for those who want to delve deeper For instance I liked the story of how the first images of the moon's far side were taken by the Russians using American high res film repurposed from a downed spy balloon along with the link to Sven's Space pageAs a Pluto enthusiast distantly related to Clyde Tombaugh I also appreciated the respect the author showed to it

  6. Christopher says:

    I found the author's nonlinear slapdash method of going from topic to topic with little build to be very much not for my own taste but I still appreciate that there is a book focused on our solar system rather than all of astronomical physics at large The chapter outlining how the author helped come up with the theory of the Earth once having two moons and that the impact and loss of the smaller with the larger gave our moon its odd features was very interesting

  7. May Ling says:

    Summary Great overview of just this galaxy It goes through the portion that is covered by space geologists The major thing is that the title is misleadingThis book tells you what we know about the galaxy to date and gives a pretty good time line of the history of how we know it This other stuff in the title relates to passing comments Too bad Could have had a better engaging title I thinkchokengtitiktitikchokeng 32 Kepler's own mother had come close to being burned at hte stake as a witch so he was closely aware of the danger of radical ideasp 53 Hubble used the brightness of stars to estimate their distance I think I knew that but I would not have been able to explain it off the top of my head Glad to get this section to clarify it allchokengtitiktitikchokeng 76 I still think it's weird that the Moon reflects the sun's light I wish he would have gone into how precisely that works physically It's Ok I am sure someone else will speak to itchokengtitiktitikchokeng 77 the use of the eclipse and the knowledge about light allowed them to figure out the distance between the sun and the moon Aristarchus some old school greek guychokengtitiktitikchokeng 79 The larget number in his day was 10k Intriguing perspectivechokengtitiktitikchokeng 89 The crater hitting the moon and earth took over a different theory that believed it came from volcanoschokengtitiktitikchokeng 97 Interesting how they do the math on determining the size of the meteor vs the crater I also think it's fascinating how the shocks work precisely I'd never thought through what it means for something so huge to impact the earth The two are actually merging the way you see in cells not the way a ball bounces off a wall p 111 bigger craters form slowly than smaller ones So like it hits and then it continues to form Weird right?p 131 Very cool to have him talk about what it's like from a pressure perspective on other planetschokengtitiktitikchokeng 173 Saturn has 1 big moon called Titan and then a lot of tiny moons while Jupiter has many mid sized moons Titan though is as big as all the other mid sized moons They think that Saturn's little moons all swallowed up together to create a big onechokengtitiktitikchokeng 176 he makes the argument that it's not actually that expensive to build a space ship p 218 Darwin thought that the moon was spun out of the earth when it with the radiant energy of the sun was spinning a lot fasterchokengtitiktitikchokeng 310 There are rocks being ejected from the moon but they burn up in atmospherechokengtitiktitikchokeng 312 although the Greeks and Chinese knew about Uranus Kepler did not p 342 talks about the shock waves that happen and the speeds 5kms or 3kms for icy planets Reference book Impact Cratering A geological Process

  8. M. Ryan says:

    I didn’t rate the book because I’m not smart enough to understand it It’s true

  9. Peter Bradley says:

    When I was in school the planetary system was the gold standard for modeling permanence and regularity We even had a law for predicting where planets could be found Of course whether it was a law or a coincidence would depend on observations from other planetary systems around other stars but in 1977 that was not something to worry aboutWell the returns are now in and the universe is far stranger than we can imagine with large planets migrating around the solar system or spiraling into orbits that take a week to travel around their stars Planets smashing into each other as dust particles build up into boulders build up into embryos that reach a size called oligarchs from which the survivors of the age of bombardment can be called planets or moons or plutinos Erik Asphaug's When the Earth had Two Moons offers the apogee of Gosh Wow Science with a tour of the Solar System's pre history Long before we had our nine planets there may have been many planets orbiting the Sun Some of those planets lost Jupiters and Saturns spiraled into the Sun Others collided and left behind one planet as the lucky shark surviving in the ocean The EarthMoon system is the result of a collision between proto Earth and a Mars sized oligarch now called Theia which struck at just the right angle to deposit a large section of Earth's crust into Earth orbit This formed the Moon which has been slowly receding from Earth so that right now it is at the exact distance to permit full eclipses of the Sun When we get reports of Super Earths that may simply be an indication that the Earths of that system didn't avoid the continuing accretion that could have happened in our systemAsphaug is noted for a pioneering theory of the formation of the Moon One of the discoveries of the Apollo program was of the Dark Side of the Moon which had never been observed before The Moon is tidally locked to the Earth and only ever shows one side to the planet The Dark Side does not have the familiar Mares or dark flat spot we are used to seeing Instead it is all mountains and has a thicker crust Asphaug theorizes that there was a time when the Earth was orbited by two moons The smaller eventually crashed into what is now the Dark Side which formed the mountainous terrain we now know to existThis is mind bending stuff Asphaug's text is accessible to the layman but I really couldn't figure out how his topics were organized It seemed that he meandered from one topic to another without any organizing ideaNonetheless this is interesting material and it would be worth buying Asphaug a beer and letting him meander into the night

  10. Timothy says:

    I have always enjoyed science but have no background in it and rarely read it As a result large portions of Asphaug’s work went right over my head I stuck with it however and really enjoyed what I was able to understand The purpose of the book is to explore some of the latest theories concerning the contents and formation of the solar system The simple version seems to be that over time matter comes together until it becomes too big then it explodes apart and does it all over again In the process you get stars planets moons comets asteroids and dust of all different shapes and sizes It’s fascinating to think of how it all happens and especially how long it all takes billions of years in many cases The scale is just mind boggling The frustrating part is that it’s almost all just theory at this point with extremely limited evidence to support it As the title suggests the climactic story is an exploration of the author’s theory about the earth having two moons hundreds of millions of years ago Eventually they slammed together and created the one we have today It’s a theory based largely on speculative computer models whose parameters could be way off the mark Despite all the possibility for error however my perception of the solar system has changed for the better and my love of the grandeur of space has only increased From the sounds of it there are uite a few upcoming missions set to take off in the 2020s that will explore the comets asteroids and moons of the solar system This will provide massive uantities of data to help clarify the picture for us So long as civilization survives science will continue bringing us closer to truth and understanding I thank Mr Asphaug for his tireless work in illuminating the current state of that uest

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