- Is anybody out there?, Heather Couper and Nigel Henbest ; illustrated by Luciano Corbella
- Are aliens real?, Portia Summers and Dana Meachen Rau
- Why is there life on Earth?, Andrew Solway
- Life on other worlds, Lisa Regan
- Are we alone in the universe?, theories about intelligent life on other planets, Tom Jackson
- Just right, searching for the Goldilocks planet, Curtis Manley ; illustrated by Jessica Lanan
- Aliens and UFOs, Marc Tyler Nobleman
- Curiosity, the story of a Mars rover, Markus Motum
- Alien encounters, by Patricia D. Netzley
- Mars and the search for life, Elaine Scott
- The search for extraterrestrial intelligence, by Dennis B. Fradin ; consultant Paul Horowitz
- Aliens, by Jacqueline Mitton
- Mysteries of alien life, Margaret J. Goldstein
- The search for life in space, Clint Twist
- ETs and UFOs, are they real?, by Larry Kettelkamp
- Space exploration and the search for life beyond Earth, Avery Elizabeth Hurt
- Curiosity Rover, searching for life on Mars, by John Hamilton
- Looking for another Earth, by Ellen Lawrence
- Invaders from outer space, real-life stories of UFOs, written by Philip Brooks
- Extraterrestrial life, by Virginia Loh-Hagan
- Is there life on other planets?, the planets of our solar system, Rosalind Mist
- The mystery of life on other planets, Chris Oxlade
- Is there life in outer space?, by Isaac Asimov ; with revisions and updating by Richard Hantula
- Aliens, UFOs, and unexplained encounters, Andrew Coddington
- Alien worlds, your guide to extraterrestrial life, by David A. Aguilar
- Are we alone?, scientists search for life in space, by Gloria Skurzynski
- The alien hunter's handbook, how to look for extraterrestrial life, written by Mark Brake ; illustrated by Colin Jack & Geraint Ford
- SETI, the search for alien intelligence, by Peter Jedicke
- How to meet aliens, by Clive Gifford ; illustrated by Scoular Anderson
- Is there life on other planets?, author, Isaac Asimov
- Aliens, by Jim Pipe
- Life on other worlds, Ray Spangenburg and Kit Moser
- Is there life on Mars?, Dennis Brindell Fradin ; illustrated with full-color and black-and-white prints and photographs
- The alien hunter's guide, by Gomer Bolstrood
- The kids' guide to aliens, by Barbara J. Davis
- Is there life in outer space?, by Franklyn M. Branley ; illustrated by Ed Miller
- Is there life in outer space?, written by Jan Leyssens ; illustrated by Joachim Sneyers
- The alien files, Paul McEvoy
- Aliens and extraterrestrials, are we alone?, by Isaac Asimov ; with revisions and updating by Greg Walz-Chojnacki
- Aliens, Jim Pipe
- Unidentified flying objects and extraterrestrial life, Carole Marsh
- Out of this world, the amazing search for an alien earth, Jacob Berkowitz ; [edited by Valerie Wyatt ; illustrations by Céleste Gagnon]
- Life on Mars, David Getz ; illustrated by Peter McCarty
- Looking for life in the universe, the search for extraterrestrial intelligence, by Ellen Jackson ; with photographs by Nic Bishop
- The mystery of life on other planets, Chris Oxlade
- Are we moving to Mars?, by Anne Schraff ; illustrations by Michael Carroll
- Searching for extraterrestrials, Cynthia O'Brien
- Solo, a Star Wars story, the official guide, written by Pablo Hidalgo
- Aliens, Dana Meachen Rau
- UFOS, are alien aircraft overhead?, Megan Borgert-Spaniol