Chapter 9 Flashcards
Dimensions of Space
6 Astronomical observations with the naked eye
1) Night/Day
2) change of seasons
3) stars, some planets
4) phases of the moon
5) comets, shooting stars, falling meteors
6) solar + lunar eclipse
6 observations using technological instruments
1) reflector, retractor, radar telescopes
2) Binoculars
3) Space probes, space shuttles, space stations
4) radar
5) satellite
6) welb telescope
What is an astronomical unit
A unit of measurement equal to the average distance between earth and the sun.
What are astronomical units used for
Express very large distances, such as distances within our solar system
What are light years
A measurement of distance. It is equal to the distance that light can travel in a year
What are light years used for
Express extremely large distances, such as distances between stars
AU=
ly=
speed of light
AU= 1.5 x 10^8km
ly= 9.46 x 10^12km
speed of light = 3.0 x 10^8 m/s
What is the big bang theory
The most commonly excepted theory on the origins of earth
What is a star
A celestial body with a brilliance that comes from the energy it produces.
What is a satellite
A celestial body in orbit around another celestial body that is not a star
What is a solar system
Made up of the sun and all the celestial bodies travelling in its orbit
What is a galaxy
A massive cluster of stars and matter that orbit its centre
3 types of galaxies
1) spiral
2) elliptical
3) irregular
Our galaxy
Name: milky way
Type: spiral
Star: sun
