The age of the Milky Way galaxy has been estimated to be at least 13 billion years based on
a. observations of globular clusters.
b. observations of open clusters.
c. 21-cm radiation from H I regions.
d. the rotation curve of the galaxy.
e. the energy produced by Sagittarius A.
E
You might also like to view...
The Mesozoic is a(n)
a. epoch. b. era. c. eon. d. period.
Underground mines produce smaller amounts of coal per year than strip mines by their very nature
What will be an ideal response?
The maximum possible value for the coefficient of static friction is:
a. 0.50 c. a value up to but not quite 1.00 b. 1.00 d. greater than 1.00
An effective way to passively cool a house is to _______
a. open all the windows b. use a light colored roofing material c. use concentrating collectors to provide air conditioning d. add more insulation on the south side of the house e. use thermal storage mass