tides
the rising and falling of ocean waters as a result of the moon’s gravity and earths gravity
ellipse
a curve that is generally referred to as an oval or the shape of an egg
phases of the moon
the monthly progression of changes in the appearance of the moon, which result from different portions of the moons sunlight side being visible from earth
eclipse
the phenomenon in which one celestial object moves directly in front of another celestial object
lunar eclipse
the phenomenon in which the full moon passes into earths shadow
solar eclipse
the phenomenon in which the shadow of the moon falls on earths surface
gravitational force
the force of the attraction between all masses in the universe
planet
an object that orbits one or more stars, is spherical, and does not share its orbit with another object
solar system
a group of planets that circle one or more stars
astronomical unit
the average distance between earth and the sun about 150×10 to the power of 6 km
orbital radius
The average distance between the sun and an object that is orbiting the sun
comet
an object composed of rocky material ice, and gas comes from
the kuiper belt and oort cloud
aestroid
A small object that ranges in size from a tiny spec like a grain of sand to 500 km what most asteroids originate in the asteroid belt between Mars and Jupiter
meteoroid
A piece of rock moving through space
constellation
A group of stars that seem to form a distinctive pattern in the sky
a light year
The distance that light travels in one year about 9.5×10 to the power of 12 km
rotation
the turning of an object around an imaginary axis running through it
revolution
the time it takes for an object to orbit another object earth revolution around the sun is 365.24 days.
calendar
A way of showing days organized into a schedule of larger units of time such as weeks, months, seasons, or years, usually a table or a chart
celestial object
any object that exists in space, such as a planet, a star or the moon
astronomer
A scientist who studies astronomy, which is the study of the night sky
apparent magnitude
the sun brightness of a star as seen from earth
latitude
the location above or below the equator
retrograde motion
The movement of an object in the sky, usually a planet from east to west rather than in its normal motion from West to East
