The Giant Book of Europa

Well, I ended up breaking down and picking up the new Europa book at the University of Arizona bookstore.  This 727-page tome by University of Arizona Press covers a number of Europa topics including its geology, the geophysics of its iceshell, its induced magnetic field, and of course, its potential to be an abode for life.  I haven't had much time to sort through it yet; I'm still trying to get through Titan from Cassini-Huygens that was sent to me last month.  However, I do like the abundant coverage of Europa geology, which holds much more interest to me than the speculation of whether Europa's sub-surface ocean contains life.  This book is edited by Bob Pappalardo, Bill McKinnon, and Krishan Khurana and each chapter has different authors that serve as a review paper for our current understanding of different topics.  Right now, I am flipping through the induced magnetic field chapter (by Krishan Khurana) since it certainly helps with understanding the recent Io results.

Yes, I know that buying a book all about Europa makes me a traitor... I know, I know...

Link: Europa (University of Arizona Space Science Series) (Hardcover) [www.amazon.com]

Io@400 Part 5: The Starry Messenger

This week we are looking back at the discovery of Io and the other Galilean satellites by Galileo Galilei 400 years ago yesterday.  Yesterday, we took at Galileo's observations of the Jovian system with his refracting telescope in Padua, Venetian Republic in the first two months of 1610, including his discovery of the four moons that bear his name on January 7, 1610.  Today, in the fifth and final part of our series of posts in commemoration of the discovery of Io, we take a look at Galileo's book, Sidereus Nuncius, where he published his discoveries with the telescope.  We will also look at the contemporary reaction to the book, both from fellow scientists and from the dominant power in Italy at the time, the Catholic Church.

...for now we have not one planet only revolving about another, while both traverse a vast orbit about the Sun, but our sense of sight presents us four stars circling about Jupiter, like the Moon about the Earth...

- From Galileo's Sidereus Nuncius (trans. by Edward S. Carlos)

The Starry Messenger

As Galileo recorded his observations of the Jovian system in the first two months of 1610, Galileo set about writing a book reporting his discoveries to the world.  This book, Sidereus Nuncius or The Starry Messenger in English, was approved for publication by the Venetian church censors on March 1, completed on March 2 with one final Jovian observation, religious approval formalized on March 8 (probably after the proofs), and published on March 12 with a new forward dedicated to the Grand Duke of Tuscany.  Also during this time, he changed his suggested naming for the four new moons from the Cosmica Sidera (or the Cosmic Stars after Grand Duke Cosimo personally) to Medicea Sidera, or the Medicean Stars after Florence's ruling family as a whole.  All of these flatteries, the dedicated forward, the naming of the moons after the Medici, and the special bound version along with one of Galileo's telescopes sent to Cosimo through Tuscany's ambassador to Venice, Belisario Vinta, were intended to get in Cosimo's good graces, perhaps with a post at the University of Pisa and a better deal than the Venetians had given him in return.

Galileo's book became an instant best-seller, selling out the 550 copies printed its first week.  The imperial astronomer, Johannes Kepler, was given a copy of the book by a Galileo associate, Martin Hasdale, in mid-April 1610.  Kepler was encouraged to write a response to the book, which he did in Dissertatio cum Nuncio Sidereo (Conversation with the Starry Messenger).  In the book, Kepler praised Galileo's discovery, though he had not had a chance to confirm it, but regretted Galileo's lack of philosophical discourse in his treatise and that he didn't acknowledge the contributions of scientists like Copernicus and Giordano Bruno for expecting these kinds of observations.  In Italy, Galileo was facing a mixed reaction.  The Venetians, angered by Galileo turning his back on them and turning to the Medici, began a campaign to discredit Galileo.  They were his patrons after all, giving him a raise for his post at the University of Padua during the previous year after he showed his telescope to the Doge and the Segnoria.  The Venetian ambassador to Tuscany, Giovanni Bartoli, told Vinta that Galileo, "was being laughed at for having claimed new discoveries in the heavens and for having duped the government with a so-called invention that could have been bought anywhere for a few lire, said to be of the same quality as his" (from Stillman Drake's Galileo at Work, pgs. 158-9).  Note that Galileo gifted his telescope to the Venetian state, not claiming it to be his invention, but an innovation better than the version a merchant from the Netherlands was trying to sell.  Kepler requested that the imperial ambassador to Venice, Georg Fugger, send a copy of Sidereus Nuncius, to Emperor Rudolf II, to which Fugger responded that Galileo had written a pretty boring book without philosophy to back him up, and besides, he just stole the telescope design from the Dutch, so why bother.  Basically, Fugger was repeating the misinformation the Venetians were putting out there about Galileo.

Criticisms

In May 1610, Galileo was given an appointment as Chief Mathematician at the University of Pisa, where he would not be obligated to teach, giving him more time to write more books on his views on the universe and to act as the Philosopher and Mathematician to the Grand Duke of Tuscany.  These appointments came with a salary of 1000 florins.  So basically, Galileo received what he hoped to get out of the Tuscans, and he was able to return to his home country.  As Galileo traveled from Padua to Pisa in April and May, 1610, he began to pick up on the growing opposition to the Sidereus Nuncius and his discoveries.  At Bologna in late April, he visited with Giovanni Magini (who was passed over by Galileo for the appointment as chief mathematician at Padua in 1588) and his student Martin Horky.  Both Magini and Horky over the next few months would write letters and books describing Galileo's discoveries as ridiculous.  Horky would say that he failed to see the Jovian moons from Galileo's telescope when the latter visited Bologna (though in some sources I found, he does claim that he observed spots near Jupiter during Galileo's visit), and would write a book titled A Very Short Excursion against the Starry Messenger.  In Excursion, Horky argued that the spots were optical illusions produced by the imperfect glass used in Galileo's telescopes, akin to the colored halos that appeared around the stars and planets.  Francesco Sizzi would write similar objections, as well as noting a few theological ones, in his 1611 book, Dianoia Astronomica, Optica, Physica.  Further opposition would come from the chief theologians at Padua and Pisa, who refused to look through Galileo's telescope. Lodovico delle Colombe in 1611 wrote Against the Earth's Motion, refuting Galileo's interpretations. Colombe over the next few years would become one of Galileo's chief critics in Tuscany, forming the League of Pigeons (a play on Colombe's name, which means dove in Italian).

Much of the opposition to Galileo's discoveries came from the lack of verifiability.  With telescopes of high enough power to observe Jupiter's moons so rare, other astronomers were having difficulty replicating his discoveries, except for Simon Marius, but he didn't publish his findings for another four years.  Kepler finally had a high-enough powered telescope by October 1610, and was able to confirm the existence of Jupiter's moons.  The Jesuit astronomer of the Collegio Romano Christopher Clavius in Rome first disputed Galileo's findings for lack of proper instrumentation, but finally observed them as well by December 1610.  Other observers of the Galilean satellites during that second observing season included Thomas Harriot in England as well as Nicolas-Claude Fabri de Peiresc and Joseph Gaultier de la Vallette in France.  de Peiresc would later suggest individual names for the Galilean moons based on the names of Cosimo and his brothers, but those have not survived to the modern day.

Galileo's run-ins with critics of his discoveries, particularly his interpretation that they supported the Copernican model of the universe, would continue for the rest of his life.  This conclusion became particularly entrenched following his observation of the phases of Venus in late 1610.  At this point, the church predominantly supported Tycho Brahe's model which entailed the five known planets (Mercury, Venus, Mars, Jupiter, and Saturn) orbiting the Sun while the Sun and the Moon orbited an unmoving Earth.  This model retained the geocentrism and most importantly the geostatic positions of the Earth, which were discussed in the Bible, but was simpler and better supported by observations than the Aristotelian/Ptolemaic model where all celestial bodies orbited the Earth. Jesuit astronomers confirmed Galileo's observations using their own telescopes, but disagreed with him regarded his conclusions about what they said about the position of Earth and the Sun in the Universe.  The lack of observed stellar parallax at the time seemed to preclude a moving Earth, not to mention that Galileo's notion that tides were result of the Earth's motion were viewed as absurd.

Galileo would persist in his support for a heliocentric universe, as most dramatically presented in his 1632 book, Dialogue Concerning the Two Chief World Systems.  In that book, Galileo presented arguments for both the Copernican heliocentric model and the Tychonic hybrid model.  His attempt to be balanced in his coverage, as requested by Pope Urban VIII, a friend of Galileo's prior to his elevation to the papacy, backfired however, when it was perceived as having mostly pushed the heliocentric view, correcting the points of the geocentric Simplicio, and insulting his former friend, the Pope.  This apparent outright defense of the Copernican world view was seen as in violation of an order by Cardinal Roberto Bellarmino in 1616 (who was later canonized in 1930), which ordered him to only describe the heliocentric universe as a theory.  While it is now agreed that Galileo didn't intend to slight the pope (and Simplicio was meant not as an insult, but as a reference to famous Aristotelian philosopher Simplicius), Galileo's apparent offense to the Pope, who was already seen as not being tough enough against heretics, removed the huge support he had against his church critics.  For his support of the Copernican heliocentric world view and his support of atomism (the view that matter was composed of small, invisible particles, which contradicted the transubstantiation of the Eucharist), he was put on trial for heresy in Rome.  Galileo was found guilty, but managed to avoid life imprisonment or worse by confessing his actions and refuting his earlier heliocentrism.  As a result of this and his age, Galileo would receive house arrest, requiring him to remain at his Villa il Gioiello in Arcetri near Florence.

Thanks to the mathematical models of Johannes Kepler, which showed that the planets revolved around the Sun in elliptical orbits at speeds that were fastest at the perihelion point in their orbits, and Issac Newton, which provided a physical foundation for the Copernican/Kepler heliocentric model (gravity), the heliocentric model gained acceptance as the 17th Century progressed.

This is the last of my series on the discovery of the Galilean satellites by Galileo Galilei, the reaction to it among his contemporaries, and the scientific arguments regarding the place of the Earth in the Universe at the time.  I hope you all enjoyed it.  If you missed any of these articles, check out my post from Sunday which provides a nice index to this week's series.

Link: Galileo at Work: A Scientific Biography [books.google.com]
Link: The Galileo Affair [www.galilean-library.org]
Link: Sidereus Nuncius [www.liberliber.it]
Link: Sidereus Nuncius (translated to English) [hsci.cas.ou.edu]

Io@400 Part 3: Simon Marius and the Mundi Iovialis

This week we are looking back at the discovery of Io and the other Galilean satellites by Galileo Galilei 400 years ago tomorrow.  Yesterday, we took a look at Galileo's first scientific observations with his new telescope in the fall of 1609 which included the viewing of mountains and craters on the Moon and stars fainter than what would normally be seen with the naked eye.  We also looked at Thomas Harriot's observations of the Moon in the summer of 1609, providing an example of the kind of tip of the iceberg the telescope's invention was in 1609.  Today, in part three of our series of posts in commemoration of the discovery of Io, we examine the research of another contemporary of Galileo's, Simon Marius, who claimed to have discovered the Galilean satellites before Galileo in December 1609.

Then for the first time I looked at Jupiter, who was in opposition to the Sun, and made out some tiny stars, sometimes following, sometimes preceding Jupiter in a straight line with him.  First, I thought that they were of the number of those fixed stars ... However, as Jupiter was then retrograding, and still I saw these stars accompanying him throughout December, I was at first much astonished; but by degrees arrived at the following view, namely, that these stars moved round Jupiter, just as the five solar planets revolve round the Sun.

- Simon Marius in the Mundus Jovialis (1614)

Meanwhile, in Germany...

In late 1608, as news of the Dutch discovery of the telescope spread across Europe, one of the inventors traveled to Frankfort in an attempt to market it.  The news of an instrument that made "the most distant objects be seen as though quite near" caught the attention of John Philip Fuchs, Lord Privy Councilor to the Margraves of Brandenburg-Ansbach.  He attempted to buy the telescope from the Dutch glass maker.  While he was allowed a demonstration of it, he found the price unacceptable.  Upon his return to Ansbach, Fuchs met with the court astronomer, Simon Marius (latinized from Simon Mayr), and they attempted to fashion their own telescope, but their were unable to get a working model since they didn't know how to polish glass and the lens makers in nearby Nuremberg didn't have the right tools.  By the summer of 1609, enough copies of the telescope were being made in the Netherlands that the prices had come down substantially since Fuchs first attempt to buy one the previous autumn.  With a newly purchased telescope, Simon Marius set to work making astronomical observations with it from both the home of the Lord Privy Councilor and at Marius's home at the Ansbach Observatory.

As described in his 1614 book, Mundus Iovialis anno M.DC.IX Detectus Ope Perspicilli Belgici (translated from the Latin title as "The World of Jupiter discovered in the year 1609 by means of a Dutch spy-glass"), Marius began to observe Jupiter in late November 1609 as the planet approach opposition, when Jupiter was opposite the Sun in the sky and thus allowing for more time for observations at night with Jupiter high in the sky.  It was during this observations that he noted at least three stars adjacent of Jupiter.  When the stars continued to move with Jupiter even when it was moving retrograde during opposition in December 1609, he realized that the "stars" were actually moving around Jupiter, just as the planets moved around the Sun.  When Marius came to this stunning realization, he began to record his observation on December 29, 1609, observing three of the moons to the west of Jupiter.  One thing to keep in mind about this observation was that Simon Marius, being a Lutheran, was using the Julian calender, just as the rest of the Protestant world used at the time.  December 29, 1609 in the Julian calendar is equivalent to January 8, 1610 in the Gregorian calendar, used by Galileo Galilei and those in other Catholic countries.  In fact, Simon Marius's description of the positions of the Galilean satellites in his first recorded observation match those of Galileo for January 8.

According to Marius in Mundus Iovialis, he continued to observe the Jupiter system until January 12 (January 22 for Galileo), at which point he determined that he was observing four bodies revolving around Jupiter. Following a trip to Swabia in Southwestern Germany, Marius returned in February 1610, and after discussing his observations with Fuchs, he was given permission to use the telescope on a more permanent at Marius's observatory.  This allowed Marius to make more continuous, detailed observations of Jupiter's satellites.  From the observations Marius acquired over the next few years from his observatory, eventually using an improved telescope of his own creation, he was able to determine that the four moons each orbited Jupiter in roughly circular orbits with different orbital velocities, with faster velocities for the innermost moons and slower velocities for the outermost.  Marius was also able to work out the orbital periods for each of the four moons, coming quite close to modern values for their periods. For example, his orbital period for Io was 1 day, 18 hours, 28 minutes, and 30 seconds, differing from the modern value by 56.5 seconds.  He noted that each of these moons orbit parallel to the ecliptic and that on occasion, the moons would appear either north or south of the equator of Jupiter, the result of Jupiter axial tilt (though not a conclusion Marius reached).  Marius would also note that Jupiter eclipses the inner moons during each orbit, causing Io and Europa to fade from view.

Galileo and the Mundus Iovialis

Simon Marius's treatise on his observations of the Jupiter system (as well as sunspots), Mundus Iovialis, was published in 1614, which included the first table of predicted positions for the satellites.  In his book, Marius acknowledged Galileo as the discoverer of the new worlds of Jupiter, "The credit, therefore, of the first discovery of these stars in Italy is deservedly assigned to Galileo and remains his."  Clearly, one could make the argument that he is quibbling when he says that Galileo was the discoverer IN ITALY, while he was the German discover of the moons.  Marius's supporters in Germany would later try to make the further claim that Marius was the sole discoverer, beating Galileo.

Galileo would respond to Marius's claims (or probably more correctly the claims of Marius's German (read: Lutheran) supporters) in his 1623 book, Il Saggiatore (or The Assayer).  First, Galileo and Marius had some history together.  Between 1602 and 1605, Simon Marius attended the University of Padua, becoming an important member in the German student society there, while Galileo was a professor there.  While a student, Marius also tutored a rich Milanese student named Baldessar Capra, where they would together observe a supernova in 1604.  After Marius returned to Ansbach in 1605, Capra remained at Padua, where he published a book in 1607 on the sector, which just so happened to be exactly the same as Galileo's mechanical compass.  After this blatant case of plagiarism, Capra was expelled from the University.  With Marius so connected to Capra as well as a result of his actions as the president of the German student's society, he was not well liked by Galileo.  So, in Il Saggiatore, published nine years after Marius's Mundus Iovialis, Galileo attacked Marius, claiming that Marius framed his student for a plagiarism he was responsible for, and saying:

Now four years after my Sidereus Nuncius appeared, this same fellow [Simon Marius] (in the habit of trying to ornament himself with other people's works) unblushingly made himself the author of the things I had discovered and printed in that book. Publishing under the title of Mundus Iovialis, he had the gall to claim that he had observed the Medicean planets which revolve about Jupiter before I had.  But note his sly way of attempting to establish his priority. I had written of making my first observation on the seventh of January, 1610. Along comes Marius, and, appropriating my very observations, he prints on the title page of his book (as well as in the opening pages) that he had made his observations in the year 1609. But he neglects to warn the reader that he is a Protestant, and hence had not accepted the Gregorian calendar. Now the seventh day of January, 1610, for us Catholics, is the same as the twenty-eighth day of December, 1609, for those heretics. And so much for his pretended priority of observation.

So Galileo clearly took offense, despite Marius's attempt in Part 1 of Mundus Iovialis to relieve that possible tension.

Now who should have credit?  Personally, I feel Galileo was right to point out the difference in calendar systems being employed between the two scientists.  Certainly the first observation Marius recorded on December 29, 1609 in the Julian Calendar matched the second of Galileo's observations from January 8, 1610 in the Gregorian Calendar.  Whether Galileo is right about Marius out right plagiarizing his work (again?), I don't think we can say.  Marius clearly was observing the Jupiter satellites starting at least in 1610, with enough observations for him to come up fairly accurate orbital periods for the satellites.  Still, based on the fact that Galileo has a  recorded observation, that has been verified using mathematical theories of the orbits of these moons, from the day before Marius's first recorded observation, gives Galileo the sole credit for the discovery.  Marius's claims that he was observing the moons as early as late November 1609 can't be verified because he didn't record what he saw.

Io, Europa, Ganymede, and Callisto

Regardless of who saw what, when, or who stole from whom, from the Mundus Iovialis, we do get the modern names for Jupiter's four largest moons.  Marius offers several naming schemes for the moons, calling them collectively the Brandenburg Stars (as a knock on Galileo calling them the Medicean Stars).  He also tried a naming scheme where he uses the names of the planets, for example "The Mercury of Jupiter" or "The Jupiter of Jupiter".  Finally, he offers a scheme suggested to Marius by Johannes Kepler in October 1613 while they were in Regensberg:

Jupiter is much blamed by the poets on account of his irregular loves.  Three maidens are specially mentioned as having been clandestinely courted by Jupiter with success.  Io, daughter of the River Inachus, Callisto of Lycaon, Europa of Agenor.  Then there was Ganymede, the handsome son of King Tros, whom Jupiter, having taken the form of an eagle, transported to heaven on his back, as poets fabulously tell, and notably Ovid.  I think therefore, that I shall not have done amiss if the First is called by me Io, the Second Europa, the Third, on account of its majesty of light, Ganymede, the Fourth Callisto.

For Tomorrow

Tomorrow, January 7, we will take a look at Galileo's observations of the Jupiter system, and how he came to view them as moons of Jupiter.

Link: Mundus Iovialis - Part 1 [adsabs.harvard.edu]
Link: Mundus Iovialis - Part 2 [adsabs.harvard.edu]
Link: Mundus Iovialis - Part 3 [adsabs.harvard.edu]
Link: Mundus Iovialis - Part 4 [adsabs.harvard.edu]
Link: Simon Marius [galileo.rice.edu]

Another Review for "Volcanism on Io"

In this month's issue of the journal Planetary and Space Sciences, there is a review for Ashley Davies's tome Volcanism on Io: A Comparison with Earth. I took a look at the book back in September, giving it a favorable review. In PSS, University of Bern researcher (and INMS instrument co-I on Io Volcano Observer) Nicolas Thomas also gave the book a favorable review. Thomas writes that the book provides a great overview of this increasingly important topic, particularly as NASA seems to be getting serious about a return to Io. He notes some minor issues with the book, such as its scant coverage of theory behind tidal heating and gas plume modelling. The latter was a problem I had, particularly when you compare it to the coverage of the modelling of Ionian lava flows.

Besides being a straight review, Thomas provides an often amusing look at the problems facing a future Io mission and the reasons why Iophiles should take heart that an Io mission may not be impossible. Besides the usual concerns about radiation and the need for RTGs for power (I was reminded last week that you need RTGs to return data at a high bitrate from Jupiter -- read pictures -- so don't look for me to post that solar-panelled Io mission anytime soon), Thomas notes the programmatic problems with the lack of water and the potential for life on Io. These of course clash with NASA's recent obsession with following the water and astrobiology. However, Thomas tries to sooth these concerns by noting NASA's need to test their next-generation radioisotope power sources (ASRGs), which led to the IVO concept study, the innovative high-inclination orbits to be tested by Juno that would reduce a spacecraft's radiation exposure, and the desire to test rad-hard technology for a future Europa Orbiter.

Link: ScienceDirect - Planetary and Space Science, Volume 56, Issue 15, Pages 1919-2028 (December 2008) [www.sciencedirect.com]

Review: Volcanism on Io

On Monday, I received my copy of the book Volcanism on Io: A Comparison with Earth by JPL researcher Ashley Davies. This book, by Cambridge University Press, was published late last year. I had considered picking up a copy since it was published, but the cost of the book ($133 on Amazon.com) was a significant barrier. Thankfully due to some lowered expenses this month, I was able to pull the trigger on buying this book.

Volcanism on Io is a review of our current knowledge, post-Galileo, of Io's volcanic activity. This is a much more focused publication compared to the other major post-Galileo Io book, Io After Galileo, edited by Rosaly Lopes and John Spencer with chapters contributed by nearly 30 authors, including yours truly. The book focuses on modeling of volcanic activity, particularly how thermal emission observed from remote instruments can be related to the style of volcanic activity. Davies also spends several chapters on reviewing our current ideas for the eruption styles at several distinct volcanoes, including Loki, Pele, Tvashtar, Prometheus, Amirani, and Pillan.

The meat of the book comes from Davies's explanation of his lava cooling model, presenting step-by-step the various aspects of it including the equations he uses. I wish more diagrams were used to show how some of the variables he uses inter-relate, making some parts of his explanation a bit hard to follow. Also, the chapter in question, Models of Effusive Eruption Processes, is largely a rewrite of the author's 2005 paper on the subject. This fact highlights my most important criticism of this book. Davies does a great job in covering the subjects that are in his wheelhouse: NIMS observations of Io's volcanic activity, internal structure, and modeling of terrestrial and ionian volcanism. Discussion of subjects that are less so, like volcanic plumes and geomorphology, seem to rushed. For example, I would have loved to have seen a chapter covering modeling of volcanic plumes in as much detail as the one on effusive eruption modeling.

Volcanism on Io, with the exception of parts of Chapter 7 where more illustrations could have been very helpful in understanding the equations he was presenting, the book is well illustrated, presenting models based on our current understanding of Ionian volcanism. This is particularly useful in his cutaway views showing the envisioned structure of Io's lithosphere in Chapter 18 and of paterae formation in Chapter 15.

Volcanism on Io provides a focused examination of several of Io's volcanoes. Applying the models Davies presented in the preceding chapters, the author provides in this book a detailed analysis of the eruption styles of specific volcanic centers. I almost wished he expanded his analysis to more volcanoes, like Isum (where several eruptions centered on Io's largest fissure were observed by Galileo), Hi'iaka (a patera with a potentially unique formation process), Kanehekili, and Masubi. It should be noted that the manuscript was likely written sometime in late 2006, before the New Horizons flyby as no results from that encounter are presented.

Ashley Davies's Volcanism on Io is an in-depth look at an important aspect of Ionian science, its volcanic activity. The book provides a review of our current state of knowledge in the subject and focuses on Davies's own models for how the observed thermal emission relate to several important eruption parameters, such as volumetric flow rate, and further, how those relate to eruption style. Davies does an excellent job in explaining how these different eruption styles work. I wish Davies had spent more time on subjects that are not in his wheel house, such as the geomorphology of volcanic terrains and volcanic plumes. Still, I definitely recommend this book for people wanting to better understand the nitty-gritty of perhaps the most important aspect of Io science, the active volcanism on display.

Link: Volcanism on Io: A Comparison with Earth [www.cambridge.org]

Volcanism on Io Arrives

Well I finally pulled the trigger on this book and ordered it on Amazon last week. Volcanism on Io: A Comparison with Earth by Ashley Davies is a comprehensive overview of the current state of knowledge into the volcanism displayed on the surface of Io. An overview of terrestrial volcanism and remote sensing studies is provided as a background to better understand what we see on Io.

The book arrived via UPS this morning and am slowly working my way through the book. I plan on providing a thorough review sometime this week on this impressive tome.

Link: Volcanism on Io: A Comparison with Earth [www.cambridge.org]

Io on Google Books

One useful resource I have found online and have been using a lot lately (for example, I credit Google Books for helping me find the name "Mayda" for the large island in northern Kraken Mare on Titan). Google Books provides online previews for various publications that they have scanned and uploaded to their website. The service is not without its flaws as many books suffer from missing pages. With that in mind, here are a few books with nice overview chapters on Io:

• Encyclopedia of the Solar System - Second Edition: I have a hardcopy of the first edition that I got as a birthday present almost a decade ago. The second edition continues the high standard set by the first and includes updates since the first's publication. The Io chapter by Rosaly Lopes provides a nice overview on the science of Io's surface and interior, but four missing pages in Google Books copy cover topics such as the Galileo mission at Io and the various Jovian magnetospheric interactions with Io.
• Jupiter: The Planet, Satellites, and Magnetosphere: This book was intended as an overview of what we knew about the Jovian system at the end of the Galileo mission. The book includes a 22-page chapter on the geology and composition of Io's surface by Galileo Imaging team member, Alfred McEwen and others. Only once page is missing due to a scanning error. The more extensive coverage of the Jovian system also allows for separate chapters on the Plasma torus and Io's interaction with its plasma torus and Jupiter magnetosphere (though some of those suffer from more missing pages).
• Worlds on Fire: Volcanoes on the Earth, the Moon, Mars, Venus and Io: This book by Charles Frankel covers volcanism throughout the solar system and includes an extensive chapter on Io and several of its volcanoes. A more general audience is intended with this offering so this might be a good choice for those looking for a more general overview than those previewed above. This book is more limited in the number of pages you can view before it cuts you out and has more missing pages than the selections above.

For laughs, you can always read Europa: The Ocean Moon by Richard Greenberg. Offers a nice scientific overview, if you can forgive the blatant Europan propaganda and the fact that it doesn't give a balanced overview of the whole thin-ice vs. thick-ice issue that brewed on the Galileo team. You can read my original review of this book on my old Titan blog.