Were you a bit saddened when Pluto lost its rank as a planet in our solar system? Perhaps before this you had thought that we had a firm understanding of our solar system and we were ready to look further. Apparently, as Michael Moltenbrey writes in his book “Dawn of Small Worlds, Dwarf Planets, Asteroids, Comets”, we’re anything but familiar with all the items wandering about our Sun. Yet, he shows that the contents of our solar system do have some reason and rationale even if we’re still finding out just what exactly is out there.
Yes, there are eight planets in our solar system. But, there are also lots of other things. Some we can easily see just like the planets. If we’re lucky, we get to see a comet fly through our night skies. It comes from somewhere and goes somewhere and we just see a glimpse of its lifetime. Then, there’s the occasional warning as we learn that an asteroid is on a possible collision course with Earth and we will end up going the way of the dinosaurs.
Maybe it all seems trite and random but that’s not the case as you will quickly read in this book. Based upon likely accretion models of our solar system, it shows that the material in our solar system today has an understandable and predictable behaviour. Further, we can readily use the phrase ‘small worlds’ for this material as apparently they are just that; very small clumps of rock-like miniature and distinctive worlds.
Why is it just “the dawn” of our understanding? Well, our sensors are only barely able to detect them against the great backdrop of the universe. Just imagine finding and measuring a rock that’s tens of kilometres across and several astronomical units from the Earth! What this book will provide you with is an excellent summary of what we’ve learned so far. It will clarify the differences between comets and asteroids and then perhaps confuse things a bit by introducing centaurs, cometesimals and plutinos. You can also read about hot and cold Kuiper Belt objects, if indeed it is actually a belt in shape. That is, this book presents many of the distinctive parameters for small worlds, especially those that provide distinction from our well known planets.
The book’s definition and presentation of the parameters is its greatest value. Much of the contents refers to the easiest measurable details; the eccentricities and inclinations. But there’s also some on the albedo, spectroscopy and composition. Perhaps most interesting is the book’s inclusion of the aims and results for most of the recent probes including Rosetta, Dawn and New Horizons. Pictures and data are dated to as recently as 2015 April which certainly implies that the book’s material is quite recent.
However, the inclusion of recent material may have come at the price of poor editing. For a finished book, this book has far too many grammatical and spelling errors. While a few errors might have been tolerable, the quantity therein indicates that at best a spell checker was used. Given these errors, some passages were confusing. Further, with the errors, you may question the veracity of the material itself. This is unfortunate as the book has so much depth and detail that it would otherwise have made a ready reference on your bookshelf.
As well, the one thing lacking in this book is an effective summary. It does contain a wonderful history of many discoveries of small worlds. It does highlight the incredible progress that we’ve made in just the last few decades in putting landers onto small worlds and sending probes out to Pluto. But where to next? Should we mine asteroids? Should we build an asteroid defence system? Should we journey to the Oort cloud? And perhaps most interestingly, what may become of our solar system after a few more hundreds of millions of years of settling down? A summary would be an excellent location for musings on these and similar topics.
Nevertheless, while Pluto may have lost its status as a planet it is indeed still a world even though small. And, there are many other small worlds joining it in our solar system as wonderfully described in Michael Moltenbrey’s book “Dawn of Small Worlds, Dwarf Planets, Asteroids, Comets”. From reading it, you will readily see just how much knowledge we’ve gained of our own backyard in this wide universe.
This book is available through Springer Publishing.
You can find out more about the author here.
No, there are NOT only eight planets in our solar system. Once again, we have a writer who does the disservice of presenting one side of an ongoing debate as fact when this is not the case. If he is so interested in the Dawn and New Horizons missions, why does he not acknowledge that most of the scientists on both of these missions consider dwarf planets to be a subclass of planets (as Dr. Alan Stern intended when he first coined the term). The public does not need yet another apologist for the controversial IAU decision who tries to reassure us that “we lost Pluto, but it’s okay.”
We did not lose Pluto as a planet. Does this writer even mention the geophysical planet definition, according to which a planet is any non-self-luminous spheroidal body orbiting a star, free floating in space, or orbiting another planet? This definition places primacy not on an object’s location but on its intrinsic properties. Dwarf planets share many of those properties with their larger terrestrial counterparts, which is why they too are planets. Counting them gives our solar system a total of 14 planets and counting, and that is without Sedna, “Biden,” Orcus, and the most recently found dwarf planet. We need to stop being afraid of the notion of having “too many planets” and recognize that having more than people can memorize is okay because memorization is not important–understanding concepts is.
Why does Moltenbrey not report that based on Vesta’s complexity and processes, some members of the Dawn team consider it “the smallest terrestrial planet?” Why does he not report the geological complexities of Pluto, not just a world but a planet more active Mars?
Pluto has not lost its status as a planet because there is absolutely no reason to give privileged status to a decision by 424 people, most of whom do not even study planets, due to some outdated notion of “authority.” Those who sent the probes to Vesta, Ceres, and Pluto and gave us the chance to observe these worlds up close regard them as planets. Shouldn’t they be the ones who get to define what these objects are?
Many people, ranging from members of the public to amateur and professional scientists, are not “saddened” by the IAU decision. Instead, we proudly oppose it, joining the 300 professional astronomers who signed a formal petition rejecting it as the bad decision it was and still remains today.