Name: ______
Astronomy Major Concepts
Standard 4: The structure and composition of the universe can be learned from the study of stars and galaxies, and their evolution.4.a. Galaxies are clusters of billions of stars, and may have different shapes.
Stars are not uniformly distributed throughout the universe but are ______by the billions in galaxies.
As galaxies are discovered they are classified by their differing sizes and shapes. The most common shapes are ______, ______, and ______. / Draw examples of the different galaxy shapes.
4.b. The sun is one of many stars in our own Milky Way galaxy. Stars may differ in size, temperature, and color.
The Sun is a star located on the rim of a spiral galaxy called the ______.
Stars vary greatly in ______, ______, and ______. For the most part those variations are related to the stars’ life cycles.
The ______of a star determines its life span and final outcome. High mass stars can result in a ______or ______. And low mass star’s “death” will eventually result in ______. / Blue White Yellow Orange Red
4.c. Use astronomical units and light years as measures of distance between the sun, stars, and Earth.
The ______(AU) is defined to be equal to the average distance from ______to the Sun. Distances between planets of the solar system are usually expressed in AU.
Interstellar and intergalactic distances are expressed in terms of how far______, the light year (ly) (______miles). /
4.d. Stars are the source of light for all bright objects in outer space. The moon and planets shine by reflected sunlight, not by their own light.
The energy from the Sun and other stars, seen as visible light, is caused by ______reactions that occur deep inside the stars’ cores. Stars are composed of mostly ______, and a smaller amount of ______, and other elements.
Planets and the Moon (do or do not) generate the light that makes them visible. We know that the ____creates the light, and the moon and planets ______this light. We can observe eclipses of the Moon or observation of the phases of the Moon and planets when a portion is shaded from the direct light reaching our view. /
4.e. Know the appearance, general composition, relative position and size, and motion of objects in the solar system, including planets, planetary satellites, comets, and asteroids.
______planets are currently known in the solar system. They vary greatly in size, distance from the Sun, period of revolution about the Sun, period of rotation about their own axis, tilt of their axis, composition, and appearance.
The inner planets (______, ______, ______, and ______) tend to be relatively small and are composed primarily of _____. The outer planets (______, ______, ______, and ______) are generally much ______and are composed primarily of _____.
All the planets are much smaller than the Sun. All objects are attracted toward one another by ______. The strength of the gravitational force betweenthem depends on their ______and the ______that separates them from one another and from the Sun.
Planets have smaller objects orbiting them called ______or moons. Earth has one moon that completes an orbit once every ____days.
Very small objects composed mostly of rock (______) or the ice from condensed gases (______) both also orbit the Sun. The orbits of many asteroids are relatively circular and lie between the orbital paths of _____ and ______(the asteroid belt). Some asteroids and all comets have highly ______orbits, causing them to range great distances from very close to the Sun to well beyond the orbit of Pluto. /