Astronomy Flashcards
What does Astronomical Unit mean?
a distance equal to the average distance between Earth and the Sun

What does Light Year mean?
a unit of distance equal to the distance travelled by light in a single year

What does Parsec mean?
the distance from Earth at which stellar parallax would equal 1 second of arc

What is Nebula?
a cloud of interstellar gas and dust

What is Constellation?
any of the 88 groups of stars as viewed from Eath and the Solar System

What is Planetesimal ?
one small celestial body that was fused together to form the planets of the solar system

What is Protoplanetary?
protoplanets are moon-sized or larger planetary embryos within discs that have undergone internal melting to differentiated interiors

What is Nuclear Fusion?
Nuclear reaction when an atomic nuclei of low atomic number fue to form a heavier nucleus with the release of energy

What is Terrestrial Planets?
a planet which has characteristics of a rocky surface like the Earth’s

What are Gas Giant Planets?
a planet composed of almost entirely of gas

What is a Comet?
a celestial object of a nuclues of ice and dust, when near the sun a “tail” of gas/dust particles pointing away from the sun

What is Asteroid?
a small/rocky body that orbits the sun

What is a Cosmologist?
an astronomer who studies the evolution and space-time of the universe

What is Angular Velocity?
the rate of change of an angular position of a rotationg body

What is Orbit?
the curved path of a celestial object around a star, planet, or moon
