The Milky Way has 400 billion stars,and astronomers now believe that each one has about 3 planets around it.Which of the following additional pieces of information is necessary to estimate the number of technologically advanced civilizations in the Milky Way?

Question

Quizplus · Accepted Answer

To estimate the number of technologically advanced civilizations in the Milky Way, we need to know the average length of time over which life exists on a planet. This is because civilizations can only arise and develop when conditions are suitable for life, and those conditions could exist for a limited time before a planet becomes uninhabitable or the civilization itself collapses. Therefore, knowing the average length of time that life exists on a planet would allow us to estimate the number of civilizations that could have arisen and developed over the history of the Milky Way. The other choices are important factors to consider, but they are not necessary to make an estimate of the number of civilizations.

The Milky Way Has 400 Billion Stars,and Astronomers Now Believe