Comets

Comet in Moominland

written and illustrated by Tove Jansson ; translated by Elizabeth Portch.

In the days of the comet

H.G. Wells ; introduction to the Bison books edition by Ben Bova.

The Skies of Pern

McCaffrey, Anne.

Magicians of the Gods: Updated and Expanded Edition - Sequel to the International Bestseller Fingerprints of the Gods

Graham Hancock

Now and Forever

Ray Bradbury

Ragnarok: The Age of Fire and Gravel

Ignatius Donnelly

What killed the dinosaurs?

by Isaac Asimov ; with revisions and updating by Richard Hantula.

Hector Servadac

by Jules Verne

Scholastic's The magic school bus out of this world: a book about space rocks

[based on the episode from the animated TV series produced by Scholastic Productions, Inc. : based on the Magic School Bus book series written by Joanna Cole and illustrated by Bruce Degen].

Asimov's Guide to Halley's comet: [the awesome story of comets]

Isaac Asimov.