Spaceflight Insider

Review: Exoplanets: Diamond Worlds, Super Earths, Pulsar Planets, and the New Search for Life Beyond Our Solar System

NASA image of exoplanets orbiting distant star. Image Credit NASA

NASA image of exoplanets orbiting a distant star. Image Credit: NASA

A new book is set for release – Exoplanets: Diamond Worlds, Super Earths, Pulsar Planets, and the New Search for Life Beyond Our Solar System by Michael Summers and James Trefil. There are, at present, 3,700 exoplanets (that we’re aware of) and counting, which makes this a welcomed addition to a space enthusiast’s library.

Exoplanets is poised to be released on March 14 of this year (2017) and has already gained praise in a recent Booklist review. To get a better understanding of the startling discoveries being made in this field, SpaceFlight Insider spoke with one of the book’s authors, Michael Summers.

Exoplanets Diamond Worlds Super Earths Pulsar Planets and the New Search for Life Beyond our Solar System image credit Smithsonian Books

Image Credit: Smithsonian Books

Summers, who is a professor of planetary science at George Mason University, has made a career out of studying planets. He has studied exoplanets for the better part of the past decade, and he noted that this relatively new field has revolutionized his field of study.

Summers told SpaceFlight Insider: “When you look at exoplanets, there are at least a dozen more categories of planets (not including those found within our Solar System: dwarf, terrestrial, and gas giants). […] there are planets that are all water, planets that are all metal; we think that we’ve found at least two planets that are all elemental carbon and at high pressure – that means diamond.

“In some cases, you [have] got a planet that’s mostly carbon with a mantle that’s 20,000 kilometers (12,427 miles) thick, and then, at the center of that world, you’ve got a crystalline-carbon core that it’s under so much pressure that it flows [like] a liquid. You’ve got planets that go around two stars instead of one, planets that orbit three [stars], planets that orbit four stars; you’ve got planets that float around between stars and are not even gravitationally bound to stars – it just goes on and on.”

The authors found they had to take a step back and take a look at the “big picture”, so as to develop a table of all these newly discovered worlds and their properties. Much as biologists use a hierarchical system to classify organisms on a species level, Summers and other scientists studying these planets’ characteristics to classify them.

Summers noted that not only new planets were being discovered each month but also entirely new categories of planets, and that list is also likely to be extensive. Summers described the amount of work in front of exoplanet researchers as “overwhelming”.

Summers told SpaceFlight Insider: “Just finding a way to organize the discussion, not so much do the science, how do you talk about all these things? What words do you use? What categories?

“We’re coming up with new techniques to detect the chemicals in their atmospheres, and we’re very close to being able to detect signatures of life in the atmospheres of planets around other stars.”

Summers’ knowledge about exoplanets extends to those worlds who dwell in the abyss between stars. Summers noted that there could be more of these so-called “rogue planets” than the traditional ones we’re all familiar with.

“Think about our galaxy of 400 billion stars, and say, on average, each of those stars has 10 planets – and that’s not unreasonable given what we know – and take that number it and multiply it by ten,” Summers said. “That may be the number of planets that are floating around between the stars, or it could be a hundred times the number of bound planets. Between our Solar System and the nearest star, Alpha Centauri, there could be half a dozen dark planets – rogue planets that we can’t see.”

Summers stated that if Jupiter and its four Jovian moons, Io, Europa, Ganymede, and Callisto, were in the interstellar medium, their potential habitability would change little – as much of their energy originates from gravitational tidal interaction. This keeps the oceans underneath the ice of three of these moons (Europa, Ganymede, and Callisto) liquid.

Published by Smithsonian Books, Summers and Trefil’s Exoplanets: Diamond Worlds, Super Earths, Pulsar Planets, and the New Search for Life Beyond Our Solar System is a concise read at just 224 pages. For any space or astronomy buff looking for something the read while they are traveling or for a primer on what the latest findings in a field that is fairly exploding, every day, with new discoveries, this is a must-have. The book can be found on Amazon, Barnes and Noble, and elsewhere for $29.95 U.S. and $38.95 Canadian.



Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

Sounds like a fascinating read, but expensive at $40 CDN for just over 200 pages

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