Vocabulary#10: Stars

star: a large, hot ball of gases, which is held together by gravity and gives off its own light.

Black hole: an object whoos gravity is so strong that light can not escape it.

parallax: the apparent shift in an object´s location when viewed from two positions.

Light year:  the distance light trvels in a year.                              

constelletion: a number of stars that appear to form a pattern.

magnitude: the brightness of a star.

nebula: a cloud of gases and dust in space.

super nova: a star that explodes.

Vocabulary#9 The Outer Solar System

Comet: a ball of rock and ice that orbit the sun.

Meteoroid: a small asteroid ( rocky object that orbit the sun ) , wich may be far out in the solar system or close to the inner planets.

meteor: a Meteoroid that enters Earth atmospher and borns with a strike of light.

meteorite: any part of the Meteoroid that reaches earth surface.

Vocabulary#8: The Inner Solar System

planet: a large body orbiting a star , such as the Sun.

asteroid: a rocky, metalic object that orbit the sun.

solar system: a star such as the sun, and all objects orbiting it.

Kepler laws: laws that summarize the movment of the planets.

Vocabulary#7: The Moon in Motion

phase of the Moon: the shape of the lighted part of the Moon seen from Earthat any time.

lunar eclipse: a blocking of a view of the full moon when the moon passes into Earth shadow.

Solar eclipse: a bloking out of a view of the sun when the earth passe throught the moon shadow.

tide: the regular rise and fall of the water level along a shorline.

Vocabulary#6: Earth and the Sun

rotation: a complete spin on an axis.

International Date Line: the 180 line of longitude.

standard time zone: a belt 15 wide in longitude in which all places have the same time.

revolution: one complete trip around the sun.

Vocabulary#5: Tools of Astronomers

Univers: everything that exist.

telescope: a divice that collects light and m ake distance objects appear closer and larger.

refraction: the bending of wavesas they go from one substances to another.

reflection: the bouncing of waves off a surface.

wavelength: the distance from one peak to the next on a wave.

frequency: the number of waves that pass through a point in a second.

electromagnetic spectrum: waves of light in order by wavelength.

Vocabulary#4: How Inclined Planes Work

Inclined Plane: a straight,slanted surface that is not moved when it is used. 

screw: an inclined plane wapped around a central bar.

wedge: one or a combination of two inclined planes that is moved when used.

compound machine: a combination of two or more simple machines.

efficiency: a ratio of the work done by a machine compered with the work put into the machine.