Instructions

Read the excerpt below from Goldilocks and the Three Bears.

Once upon a time, there was a little girl named Goldilocks.  She went for a walk in the forest. Pretty soon, she came upon a house.  She knocked and, when no one answered, she walked right in.At the table in the kitchen, there were three bowls of porridge.  Goldilocks was hungry. She tasted the porridge from the first bowl."This porridge is too hot!" she exclaimed. So, she tasted the porridge from the second bowl."This porridge is too cold," she said. So, she tasted the last bowl of porridge."Ahhh, this porridge is just right," she said happily and she ate it all up.

(From Goldilocks and the Three Bears, http://www.dltk-teach.com/rhymes/goldilocks_story.htm)

Scientists are searching for a planet that is not too hot and not too cold so that it can sustain human life. There are also other factors other than temperature that scientists are investigating to determine if a planet can sustain human life.

What are some of the other factors scientists may investigate to determine if a planet can sustain human life?