BY ALEXANDER CHIN
It’s also possible that while some globular clusters orbiting the Milky Way really are globulars, they were stolen from those other galaxies it ate. That seems a little rude, to be honest — like walking by someone eating in a restaurant and stealing food off their plate. Galaxies, apparently, sometimes lack decorum.
Philip Plait’s “Under Alien Skies: A Sightseer’s Guide to the Universe” takes us on a tour of the cosmos, taking us through our solar system, galaxy, and beyond. He assists the reader in imagining themselves as tourists in a variety of locations, such as the moon, a dwarf star, or a black hole. Each experience contains supporting evidence and a background that explains how we came to know what we do.
Plait’s enthusiasm for astronomy is evident throughout his writing. In fact, it practically drips off the page, a contagious intensity that compels you to put the book down and gaze above. The excitement he must have had studying, envisioning, and even dreaming about what the experience of a human gazing up might be shines off the page. There are ten places in the book. Plait approaches the issue of how to depict the skies in (what seems to me to be) a novel way. He doesn’t invite me to go outdoors, gaze up, and imagine an apparently outlandish idea of our cosmos; instead, he depicts how I could feel if I were to stare up into strange “alien skies.” I’m not alone on my cosmic journey, though; Plait is my tour guide and he draws the heavens and stars in my vicinity.
Aspects of the cosmos, such as planets and moons, stars, and galaxies, are all explored in separate chapters of the book. Plait gives a plethora of knowledge on each topic inside each chapter, including the background to its discovery, the most recent findings in science, and what is known (and what is unknown) about each issue.
Under Alien Skies combines brief second-person science fiction stories with nonfiction sections that describe what it might be like to go to several alien worlds, including the Moon, Saturn, the planets of a red dwarf, and one in a globular cluster. While the focus is, as the title suggests, on what you would see in the sky, there are other details like how you might walk differently with different gravity levels, how you might have to step carefully to avoid falling into a rubble-pile asteroid, or why a Martian dust devil might be fun but you’d want to stay inside during a dust storm.
One of the book’s merits is Plait’s aptitude at explaining difficult scientific ideas in a way that is accessible and easy to grasp. Although he doesn’t avoid using technical phrases or equations, he clearly and simply explains them. In order to make his points more understandable to readers, he also makes extensive use of analogies and instances from the actual world.
“Under Alien Skies” is chock-full of beautiful pictures and graphics in addition to its scientific information. In addition to stunning artistic renderings of what specific celestial objects could appear like up close, Plait also includes images from telescopes and space missions. Reading the book is made much more delightful by the images, which serve to bring the subjects to life.
The chapter on exoplanets, or planets that orbit stars outside of our solar system, is one of the most fascinating in the book. Plait explores how these planets are discovered by scientists as well as what is known about them and whether or not they may support life. Additionally, he considers the implications for our knowledge of the cosmos of the possibility of discovering intelligent life on other worlds.
Another particularly notable chapter is the one on black holes, which are among the universe’s most enigmatic and interesting objects. Plait describes what is known (and unknown) about these things, including how they arise and what transpires when other objects approach them too closely. The most recent gravitational wave observation brought about by the merger of two black holes is among the most recent scientific developments he covers.
Later on in my interstellar adventure, Plait takes me outside of our solar system to explore exoplanets in some truly imaginative settings. On one such excursion, I take in a day beneath “Tatooine’s Sky” and ponder what it might be like to live on a world with two suns. He first grounds me in the science of how I know that such binary stars and planets even exist, and then he moves into the world of fiction as he creates an amazing fantasy of the event. Plait takes me on a tour of the extraordinary sky I’d see; for instance, eclipses would happen on a regular basis, much like sunrise (or, as he refers to it, “sunsrise” for this planet) and sunset. But when he went a step further and considered how life on such a planet may adapt to the wildly fluctuating environment that might emerge from circumbinary orbit, that’s when I really felt immersed.
After I become accustomed to the two-sun sky on this binary planet, Plait challenges me to picture myself relaxing on a planet orbiting a star in a globular cluster (or, as he puts it, “a planet with a million suns”). From our accustomed vantage point on Earth, the night skies will really alter in this area the most startlingly. With millions of stars to look at, today is the ideal time to envision what it could be like to view them with our bare eyes at various phases of their existence. But Plait is aware that this kind of voyage isn’t all fun and games, so he makes sure to inject me with some reality as I consider if such a planet could ever exist — and, if it did, what difficulties it could face.
For everyone interested in astronomy and space travel, “Under Alien Skies” is a must-read. With a literary style that makes even difficult subjects understandable, it is educational, captivating, and elegantly presented. Regardless of your level of experience, this book will increase your respect and comprehension of the cosmos we live in.
