Astronomy: Mapping the Stars
What are two things we have a better understanding of as a result of the advances in astronomy?
1. How far away stars are 2. How big the universe is
The three reference points used to describe a star or a planet's position in relation to a person's position are:
1. zenith 2. altitude 3. horizon
How many constellations are there?
88
Celestial equator
An imaginary extension of the Earth's equator into space.
Celestial sphere
An imaginary sphere that surrounds the Earth.
Astrolabe
An instrument used to determine a star or planet's location.
Why do constellations seem to change locations with the seasons?
Because the Earth revolves around the sun.
Doppler effect
Describes how the pitch of a sound seems higher as it gets closer and lower as it gets farther away.
Declination
Measured in degrees by how far north or south an object is from the celestial equator.
Right Ascension
Measured in hours by how far east an object is from the vernal equinox.
What are constellations?
Regions of the sky that contain recognizable star patterns.
The ancient Greek constellation Orion was the same as:
The Japanese constellation of a drum
Light-year
The distance light can travel in one year.
Vernal Equinox
The location of the sun on the first
Circumpolar stars
These stars located near the Earth's poles can be seen at all times of the year and at all times of the night.
How did ancient cultures group stars in the sky?
They linked stars together in familiar patterns and named them from familiar characters in myths and for everyday objects.
How did people in ancient cultures use the locations and movements of constellations?
To navigate and keep track of time.
Every star or galaxy belongs to ...
a constellation
The distance of one light year is ...
about 9.46 trillion kilometers.
When a star or galaxy moves quickly TOWARD an observer, the light it emits ...
appears bluer than it usually would. ("Blueshift")
When a star or galaxy moves quickly AWAY from an observer, the light it emits ...
appears redder than it usually would. ("Redshift)
People in the Northern Hemisphere see ...
different constellations than people in the Southern Hemisphere.
The apparent locations of constellations in the night sky change their locations ...
from season to season
The most distant object we can see is ...
more than 10 billion light-years
Edwin Hubble determined that the universe must be expanding by ...
observing that all galaxies, except close ones are affected by "redshift" as they move.