Astonomy Flashcards
What is an Astronomical unit?
A unit that is equal to 149.6 million kilometers.
Define a Light Year.
The distance light travels in one year.
Parsec is…
a unit distance in astronomy equal to 3.25 light years
Nebula….
a cloud of gas and dust in space
What is a Constellation?
a group of stars in a pattern. (Ex Aries.)
What is Planetesimal?
A body that could come together with many others under graviration to form a planet.
Define Protoplanetary.
Moon-sized or larger planetary embryos.
Nuclear fusion is…..
A nuclear reaction, tomic nuclei of low atomic number fuse and form a heavier nucleus.
What areTerrestrial planets?
Planets that have rocky surfaces like Earth’s.
What is a gas planet, and what are they in our solar system?
A gas planet is a giant planet that is mainly made of gas. They include Jupiter, Saturn, Uranus and Neptune.
What is a Comet?
A Comet is a object consisting a nucleus of ice and dust that when near the sun it gains a ‘tail’.
What is an Asteroid?
A small rock orbiting the Sun along with the planets.
What is a Cosmologist?
A person who studies ecolution and space-time.
What is Angular velocity?
The rate of change and angular position of a rotateing body.
Define Orbit.
To move around.
Define Period.
A length or portion of time.
Revolve is….
To move in a circle on an axis.
Rotation is….
To move around a center.
Sidereal Day is…..
The time between two consecutive transits of the first point of Aries.
Solar Day is….
The time vetween meridian transite of the sun at a particular place.
Define Year.
365 days >366 days leap years<
