WHEN THE EARTH HAD TWO MOONS by Erik Asphaug

WHEN THE EARTH HAD TWO MOONS

Cannibal Planets, Icy Giants, Dirty Comets, Dreadful Orbits, and the Origins of the Night Sky
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KIRKUS REVIEW

The sun and every body in its vicinity formed from the same primordial dust, yet every planet, moon, comet, and asteroid is different. This accomplished overview of planetary science describes the details.

The first photograph from another planet was the rocky surface of Venus, transmitted from a Russian lander in 1975. More Soviet Venus probes followed, and while NASA has been responsible for most of the rest, other nations are getting into the act. The result, featuring contributions from high-tech telescopes and computer simulations, is an explosion of information about our solar system and, more recently, solar systems throughout our galaxy. An enthusiast as well as a fine writer, Asphaug (Planetary Science/Univ. of Arizona) lays it out from the beginning. Despite their flawed theories, when the ancients observed and calculated, they proved that Earth was a sphere and measured its diameter and the distance to the moon and predicted eclipses. Geniuses from Copernicus to Einstein improved the big picture, but it was well into the 20th century before interesting details became clear. That meteor strikes formed the moon’s craters remained controversial until the Apollo landings proved it. After a nod to the Big Bang and formation of the sun, Asphaug concentrates on the history and current knowledge of the planets, familiar and unfamiliar moons, and unattached bodies in between. As an earthling, he favors earthlike features, and readers will share his pleasure as he discusses them. Rivers, lakes, oceans, and rain? Saturn’s moon, Titan, has them; Mars and perhaps Venus once enjoyed the same. Life began in water, so scientists are thrilled when they find it elsewhere. Ice doesn’t qualify, but there is evidence for liquid water oceans under the icy surface of Jupiter’s Ganymede and Europa, Saturn’s Enceladus, perhaps Mars, and even some asteroids and comets.

An expert, entertaining review of what’s known about the solar system.

Pub Date: Oct. 29th, 2019
ISBN: 978-0-06-265792-3
Page count: 368pp
Publisher: Custom House/Morrow
Review Posted Online:
Kirkus Reviews Issue: Sept. 1st, 2019