astronemy Flashcards
what is the definition of astronimal unit?
Average distance between sun and earth
What does light-year mean?
astronomical distance equivalent to the distance that light travels
what is a parsec?
large distance between one another
What does Nebula mean?
A general term used for the fuzzy patch on the sky either light or dark?
Define a constellation?
A group of stars in the night sky into a recognizable pattern
What is definition of planetesimal?
One of the small bodies (usually mirometers to kilometers in diameter)that formed from from the solar nebula and eventually grew into protoplanets
Define protoplanetary?
Moon sized or larger planetary embryos within protoplanetary discs that have undergone internal melting to produce differentiated interiors
What does nuclear fusion mean?
A nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy
Define Terrestrial planets?
A planet having a compact rocky surface like the earth’s;the four innermost planets in the solar system
What does gas giants planets mean?
A type of planet characterized by being composed almost entirely of gas
What does comet mean?
A celestial body moving about the sun usually in highly eccentric orbit
Define asteroid?
Any thousand of small bodies of from 480 miles to less than one mile
What does comologist mean?
Physical comology as a branch of astronomy is the study of the largest scale structures and dynamics of the universe and is concerned with fundamental questions about its formation
Define angular velocity?
The rate of change of angular position of a rotating body
What does orbit mean?
The curved path of a celestial object or spacecraft around a star planet or moon
Define Revolve?
Move in a circle on a central axis
Define period?
Belonging to or characteristic of a past historical time
Whats the definition of solar day
The time between successive meridian of the sun at a particular place
What does sidereal day mean?
The time between two consecutive transits of the first point of aries almost four minutes shorter than the solar day because of the earths orbital motion
What is rotation?
The action of rotating around an axis or center
What is the definition of year?
The period of 365 days starting from the of january used for reckoning time in ordinary affairs
