Book Review -- Planets: A Very Short Introduction

David A Rothery's book is part of the Very Short Introduction series from Oxford University Press.  Rothery's book is just bigger than a smart phone and in 100 pages creates a very authoritative survey derived from his first hand knowledge designing planetary probes.  He is a real physicist's physicist but the book is readable.

Here are some Planet Facts that Rothery's helpful book has summarized :

1. viewed from above the north pole, looking down, all of the planets in this solar system revolve counterclockwise.
2. what I always considered the intrinsic color of Jupiter is just a thin skin of colored bands made by clouds of solidified ammonia.   The dark bands are sinking and the lighter bands are upwellings.
3. if you could peak under this opaque striped outer skin, Jupiter's atmosphere is transparent! 
4. the transparent stuff is 10 to 1 ratio of very boring hydrogen gas and helium gas, like most of the universe is.  
5. at high altitudes the hydrogen gas is molecules of H2, same as on Earth, but lower down something crazy happens.  The hard-to-imagine intense pressure pushes the atoms together to form one big planet wide molecule of hydrogen that is so compressed that the electrons just wander around, delocalized, like in a metal.
6. and then, finally, yes, there is a rocky planet down in there, estimated to be just triple the size of Earth in Jupiter and Saturn, and just one Earth mass inside Uranus and Neptune.
7. the interior of Jupiter is very hot, just like Earth, but unlike Earth, Jupiter's heat does not come just from radioactive decay.  Models of the gas giant imply that some heat is left over from the formation of the solar system -- Jupiter is so darn big relative to its amount of surface area that the heat from its birth still hasn't leaked out all the way.  
8. on top of that, some heat, strangely, is still being emitted from latent sources (there's a real chemistry topic) as the phases seperate out and chang their state.  for example, there is probably a 'rain' of helium droplets falling out of the hydrogen atmosphere, accumulating ias a layer of helium at the bottom of the atmosphere, releasing heat as it settles.
9.  without directly seeing the pieces of the ring around Saturn or Jupiter   scientists did a clever, indirect measurement of the particle size.  Saturn's rings are made of particles up to 5 meters in size but Jupiter's rings are made of particles about 1 millionth of a meter in size.  This was determined by watching the ring when it was in direct sunlight and then how fast it cooled off when it passed into the shadow of the planet.
10. if the entire ring of Saturn were gathered and mushed into one single ball of stuff it would only be about as big as the city of Detroit

In case you don't know this book series, there are hundreds of titles from Oxford Press that begin with the words A Short Introduction To...  Besides publishing excellent primers on common subjects  they make short introductions to things like a 100 page summary of The Book of Mormon.  Also, summaries on things that are problematic to summarize: one tiny book is a summary of  Happiness and another is simply titled History.

Comments

[Peter]

Wow. I had never heard of the series. When I know nothing or next to it about something, I love something both authoritative and approachable. I'm so conscious of impressive brands selling out; I'm glad OUP is still holding on.

#9 does sound clever. The results sound amazing. 5 meters vs. a millionth of a meter!

I gotta try the one on happiness!