Author Question: All globular clusters in our Milky Way are about how old? A) less than a million years B) ... (Read 57 times)

magmichele12 · **on:** Jul 27, 2018

All globular clusters in our Milky Way are about how old?

A) less than a million years
B) ten-fifty million years old
C) one to three billion years old
D) around ten billion years old
E) a variety of ages, from newly born to twenty billions years old

Question 2

Explain why stars form only in molecular clouds, the coldest, densest parts of the interstellar medium.

What will be an ideal response?

maya.nigrin17@yahoo.com · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

D

Answer to Question 2

A cloud collapses and ultimately forms stars when gravity overcomes thermal pressure. The latter depends both on the density and temperature of the cloud. The high densities in molecular clouds means that the gravitational forces are relatively strong but the pressure is no higher than elsewhere because the temperatures are low.