Meet Pluto and Our Other (Celestial) Neighbors

Let's all raise a glass to celebrate a milestone in our relations with Pluto, our cosmic neighbor. Ninety years ago this month, on February 18, 1930, an aspiring astronomer named Clyde Tombaugh examined a pair of night sky photographs taken weeks earlier and noticed a faint light had changed position. For us, it was Pluto's welcoming wave.

Located in the vast Kuiper Belt far beyond Neptune, and traveling in an off-kilter, ellipse-shaped orbit that sends it up to 4.5 billion miles from the sun, it's fair to say Pluto and Earth have never been particularly close. Many still feel we committed a serious faux pas in 2006 when the International Astronomical Union crafted a new definition of planethood and omitted Pluto from the invite list. 

If there's a bright side to Pluto's reclassification as a dwarf planet, it's this: the change was prompted by the discovery of three additional space neighbors, Eris, Haumea, and Makemake, which hang with Pluto in trans-Neptunian orbit. (Another upside: our nearer neighbor Ceres, located in the asteroid belt between Mars and Jupiter, received an upgrade to dwarf planet status.) 

In the years since then, scientists have continued to uncover new revelations about Pluto and the many smaller tenants of our solar system, as well as an ever-growing list of new worlds we have detected around other suns. In celebration of Pluto and the spirit of discovery, the books below reveal some of the curious and astonishing highlights of this recent research. 

Pluto and the Dwarf Planets

13 Planets: The Latest View of the Solar System by David A. Aguilar. This colorfully illustrated book, written for a young audience, is a useful introduction to our solar system's "classical eight" planets and their five smaller cousins.

Chasing New Horizons: Inside the Epic First Mission to Pluto by Alan Stern. The unexpectedly gripping story of NASA's New Horizons mission and its robot spacecraft, which reached Pluto in 2015 and added a wealth of knowledge about the distant planetoid.

How I Killed Pluto and Why It Had It Coming by Mike Brown. A memoir by the astronomer whose discoveries of Eris and Makemake prompted the reconsideration of Pluto.

Asteroids, Comets, and Meteors - Oh, My!

Catching Stardust : Comets, Asteroids and the Birth of the Solar System by Natalie Starkey. A cosmochemist tells how she and other scientists have learned about our solar system's smaller residents by deploying robot space probes to scoop up dust from a comet's trail and hitch a ride on a distant asteroid.

Meteorites: The Story of Our Solar System by Caroline Smith, Sara Russell and Natasha Almeida. When rocky asteroids survive their fall to earth, we call them meteorites. In this book, copiously illustrated with color photographs, three leading experts in the field tell how a close study of these once-celestial objects can reveal insights about the universe.

Fire in the Sky: Cosmic Collisions, Killer Asteroids, and the Race to Defend Earth by Gordon L. Dillow. A surprisingly entertaining overview of the alarming history of meteorite impacts on Earth and the risk that a future collision could spell doom for us all.

Exoplanets, Our Newest Neighbors

Universal Life: An Inside Look Behind the Race to Discover Life Beyond Earth by Alan Boss. A NASA astrophysicist recounts the amazing success of the Kepler Space Telescope, an Earth-orbiting satellite which has helped astronomers discover over 2,500 exoplanets -- distant celestial objects that orbit other stars.

The Planet Factory: Exoplanets and the Search for a Second Earth by Elizabeth Tasker. An astrophysicist's brisk, no-nonsense overview of the science behind the discovery of exoplanets.

Exoplanets: Diamond Worlds, Super-Earths, Pulsar Planets, and the New Search for Life Beyond Our Solar System by Michael Summers and James Trefil. A well-illustrated review of exoplanet research that emphasizes the wide variety of worlds discovered so far.