Author Question: Briefly summarize current knowledge about the term NHP in the equation Number of Civilizations = ... (Read 23 times)

beccaep · **on:** Jul 27, 2018

Briefly summarize current knowledge about the term NHP in the equation
Number of Civilizations = NHP flife fcivilization fnow.

What will be an ideal response?

Question 2

A rock sample from the moon includes a mineral that contains small amounts of the radioactive isotope Potassium-40 and its daughter element Argon-40 (half-life of 1.3 billion years). This mineral would not form with any Argon-40.

Consider a crystal with 7 atoms of Argon-40 for every 1 atom of Potassium-40. How many atoms of Potassium-40 were present when the crystal formed for each atom of Potassium-40 that exists today?
A) 1 B) 7 C) 8 D) None

smrerig · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

NHP is the number of planets in the Milky Way that lie within the habitability zones of their parent stars. Currently, we have evidence for more than one thousand planets around other stars, and evidence for protoplanetary disks around many more stars. Although we cannot yet give a precise value to NHP, it now seems likely that it is quite largeperhaps as large as the number of stars in the Milky Way Galaxy.

Answer to Question 2

C