| EXOPLANETS Hidden Worlds and the Quest for Extraterrestrial Life Donald Goldsmith Cambridge: Harvard University Press, September 2018 |
Rating: 5.0 High |
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| ISBN-13 978-0-674-97690-0 | ||||
| ISBN-10 0-674-97690-8 | 254pp. | HC/GSI | $24.95 | |
By now it's common knowledge that hundreds of stars other than our own Sun have planets. The stars we've been able to examine to date lie relatively close to us1 — and thus, by extrapolation, the Milky Way must contain millions of stars with planets. In this book, astronomer Donald Goldsmith provides a primer on the various ways of detecting such extrasolar planets, or exoplanets, and the limitations of each. He presents the most interesting planets discovered so far, and describes future instruments which will enhance our abilities: not only spaceborne instruments like the James Webb Space Telescope, finally due for launch this year, but new ground-based telescopes with impressively large mirrors. We are not very far away from being able to identify within exoplanet atmospheres the unstable chemicals that might signal the presence of life — chemicals like oxygen and methane.
The book is also rife with speculation, and that is a good thing. Dr. Goldsmith discusses asteroid mining, tiny robotic probes pushed by lasers to one-fifth of light speed and aimed to pass by the nearer stars; human settlements on other worlds of our solar system, and even on suitable exoplanets when we find them. These are far-future prospects, and it is impossible to predict exactly how they will play out (or even whether they will occur at all), but we all should be aware of them as possibilities.
Although not intended as a reference book, Exoplanets goes some way to being one. Its precise descriptions of the history of the search for exoplanets, and the strengths and shortcomings of the various methods used, make it a useful tutorial on the subject. That history includes the development of Einstein's Theory of Relativity, which figures prominently in the exoplanet search. (And it extends back to early discoveries of the true scale of our own solar system — which illustrate the pitfalls of observation.)
"In 1761, as the French astronomer Guillame Le Gentil sailed toward India in order to observe a transit of Venus, his ship encountered such severe weather that he found himself still at sea during the event, his instruments rendered useless by the motion of the waves. Instead of taking the long journey back to France, he scouted for the best location to observe the transit of 1769 and settled on his original site at Pondicherry, where, after a run of fine weather, clouds covered the sun on the crucial morning. Depressed, Le Gentil gathered the strength to return home, where he learned that he had been declared dead and that his wife had remarried. Legal action and the king's intervention eventually restored his original official position, but his story remains a favorite among astronomers who recognize the many unexpected obstacles to achieving observational success." – Page 53 |
In addition it documents its sources very well in a set of Endnotes. It provides a list for Further Reading — 23 books & articles, and 5 Web sites — and it has an excellent index. There are a few grammatical errors (most often missing words), but I found no factual errors. Full marks, and I consider it a keeper.
To contact Chris Winter, send email to this address.