Clyde Tombaugh and the search for planet X
Margaret K. Wetterer
Clyde Tombaugh and the search for planet X
Age Rating, Reading Level & Content Guide
by Margaret K. Wetterer
On My Own Books
The text is written at a 4th grade reading level, the subject matter is intended for younger children (ages 5–8), and the content is gentle with no concerning themes.
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About This Book
Follow the journey of a curious farm boy whose love for the stars leads him to discover a new planet! See how determination and wonder can turn dreams into amazing discoveries in space.
Themes
Quick Assessment
This is a Level 4-5 book with gentle content intensity. No notable content concerns flagged. Written for readers ages 5-8.
Why we rated Clyde Tombaugh and the search for planet X 9C
Clyde Tombaugh and the search for planet X is written at a Level 4-5 reading level across 48 pages (approximately 1,641 words). Strong independent readers around grade 5.5 can typically handle this book on their own; with parent or teacher support, Clyde Tombaugh and the search for planet X works for readers up to grade 6.5.
Read aloud, Clyde Tombaugh and the search for planet X takes about 11 minutes, which fits within a single read-aloud session.
We rate Clyde Tombaugh and the search for planet X as 9C ("Clear") because the content sits in the "Gentle" range — no conflict beyond everyday childhood experiences. Across our four dimensions (emotional, physical, social, thematic) the book reads as evenly gentle; no single dimension stands out as a concern.
No specific content flags were raised by community reviewers, which is consistent with the gentle intensity score.
Thematically, Clyde Tombaugh and the search for planet X explores biography, science & nature, adventure, and coming of age — these threads give the book room to mean different things to different readers.
Good fit for
- ✓ Children in the Ages 5-8 range — the maturity and attention span match the story's pacing.
- ✓ Reluctant readers who need fast-paced, hook-heavy stories to stay engaged.
- ✓ Kids drawn to stories about biography, science & nature, adventure.
- ✓ Curious kids who prefer real-world topics over made-up stories.
Maybe not for
- ! Readers whose emotional readiness lags behind their decoding skills — this book's intensity outruns its reading level, a classic "gifted kid" mismatch.
For Parents
Content Intensity
9C — ClearNo conflict beyond everyday childhood experiences. Safe for sensitive readers.
Was our "Gentle" content intensity rating accurate for this book?
Reading Insights
Hook Factor
8/10High engagement — fast-paced, fun, and hard to put down. Great for reluctant readers.
Discussion Potential
2/10A lighter read — great for independent enjoyment.
Book DNA
Multi-dimensional content fingerprint
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Details
Book Length
- ISBN
- 0876148933
- Pages
- 48
- Publisher
- Millbrook Press
- Published
- 1996
- Type
- Nonfiction
- Word Count
- 1,641
- Read-Aloud
- ~11 min
- Text Density
- Picture-Heavy