Science Explorations
Level 1
Level 2
Journey into Space

Science Standards 4th Edition

Grades 3–5
Knows that the Earth's gravity pulls any object toward it without touching it

Knows that the Earth is one of several planets that orbit the Sun and that the Moon orbits the Earth

Grades 6–8
Knows that gravitational force keeps planets in orbit around the Sun and moons in orbit around the planets

Understands general concepts related to gravitational force (e.g., every object exerts gravitational force on every other object; this force depends on the mass of the objects and their distance from one another; gravitational force is hard to detect unless at least one of the objects, such as the Earth, has a lot of mass)

Knows characteristics and movement patterns of the nine planets in our Solar System (e.g., planets differ in size, composition, and surface features; planets move around the Sun in elliptical orbits; some planets have moons, rings of particles, and other satellites orbiting them)

Knows characteristics and movement patterns of asteroids, comets, and meteors

Grades 9–12
Knows that the strength of the gravitational force between two masses is proportional to the masses and inversely proportional to the square of the distance between them

Knows the ongoing processes involved in star formation and destruction (e.g., stars condense by gravity out of clouds of molecules of the lightest elements; nuclear fusion of light elements into heavier ones occurs in the stars' extremely hot, dense cores, releasing great amounts of energy; some stars eventually explode, producing clouds of material from which new stars and planets condense)