GALAXIES. These are galaxy clusters and separate galaxies taken by long-range telescope. The area of the sky covered is less than the diameter of the moon. DISTANCE IN THE UNIVERSE. Light year : ______________________________________ ________________________________________________
These are galaxy clusters and separate galaxies taken by long-range telescope. The area of the sky covered is less than the diameter of the moon.
Unit of distance (NOT TIME). It is the
distance that light travels in one year.
distance light travels in a vacuum in one second
Astronomical Unit: _________________________________
It is approximately 93 million miles.
Mercury is about 1/3 of an AU from the Sun.
It is not big enough when we talk about anything
outside of our solar system.
Average distance between the
Earth and the Sun.
together by gravity
Galaxies: _____________________ _____________________________
________________ was an astronomer in the 1920s who gathered many pictures of galaxies
most abundant type
arms of extending from their central nucleus
shape of a bar
The Milky Way: divided the galaxies by variations within each galaxy type
__________is only one of 200 billion stars in the Milky Way
It is a large, disk-shaped, ______________________ about 100,000 light-years wide and about 10,000 light-years thick at the center (central bulge)
There are 3 distinct spiral arms of stars
The sun is positioned on one of these arms about 2/3 of the way from the galactic center, at a distance of 30,000 light-years.
Scientist suspect there is a
super massive ______________ at
the center of the galaxy
It takes over 200 million
years for the sun to revolve
around thegalactic center.
II. The Expanding Universe way from the galactic center, at a distance of 30,000 light-years.
A. The Big Bang Theory: ____________________________
Idea that all matter began in an infinitely small point and exploded out in all directions
B. Doppler Shifthttp://www.tech.purdue.edu/Cgt/Courses/cgt211/private/images/projects/archive/3-SciVis/F02/Big-Bang--final.jpg
1. red shift: ______________________________________
2. blue shift: _____________________________________
Galaxies moving away from us should show a shift in their spectrum toward the red end
Galaxies moving toward us should show a shift toward the blue end of the spectrum
Since the spectrum for all galaxies show a ________________ http://www.tech.purdue.edu/Cgt/Courses/cgt211/private/images/projects/archive/3-SciVis/F02/Big-Bang--final.jpg
from Earth, we assume the universe is ___________________