Mujeres en las ciencias (Women in Science)

As a land that’s constantly in flux, Earth sometimes reveals clues about the plants, animals, and other organisms that lived long ago. Fossils teach us much about what life was like millions of years ago, answering the questions of how Earth changed and maybe even why it changed. This essential Earth science topic is thoroughly explained through manageable text, fact boxes, informational charts and diagrams, and a glossary and index. Readers will become young Earth detectives by the time they’re through with this text!

Introduces the concept of heat, how it's created, how it affects materials around it, and how heat is used.

These passenger trains can travel more than 180 miles per hour! These modern marvels of technology will fascinate any reader.

¿Sabías que Marte parece una estrella roja brillante? A menudo se lo llama el Planeta Rojo. Descubre más cosas en Marte, uno de los libros de Los planetas. Did you know that Mars looks like a bright red star? It is sometimes called the Red Planet. Find out more in Mars, a Planets book.

La hibernación es un ciclo que algunos animales hacen cada año. La mayoría de la gente sabe que los osos hibernan. ¿Pero por qué hibernan? ¿Y qué otros animales hibernan? Hibernation is a cycle that some animals go through every year. Most people know that bears hibernate. But why do they hibernate? And what other animals hibernate?