OBJECTIVE:  I will be able to state the conditions necessary to exist for life to survive and thrive in our galaxy.


  • astrobiology



Before we continue on our discussions of exo-planets, let's talk a wee bit about how astrobiologists (Yes, that's what they are called!) examine our OWN planet in terms of extreme biology!


Now let us ponder this: What are the basic conditions that (we think) MUST be present in order for life to survive and thrive?


Now let's take a look at some of these environments here on Earth

Please suggest a full sentence responses to each of these prompts for each of the following:

  • Indicate whether *each* of our requirements for life (as we determined at the begining of class) is present or absent in that location

  • Suggest a possible temperature for each location and indicate whether that increases, decreases or eliminates the likelihood of life to exist there.

  • Suggest whether presure is a factor for the presence of life in that location

  • Use a five point scale to indicate how likely you believe life is to exist at that location (we will define life to be any form of plant, animal, fungul, bacterial or related life form)


1) The Mponeng Gold Mine approximmately 2.5 miles below the Earth's surface in South Africa. The temperature of the rock is approximately 150 degrees farenheight. Pressure is similar to pressure at the surface. There is no sunlight.

2) A steaming, bubbling, boiling pool of nasty, poisonous chemicals in the Morning Glory Pool in Yellowstone National Park. Temperature is approximately 160 degrees. :

3) The Challenger Deep at the bottom of the Mariana's Trench (more than 37,000 feet deep, the deepest part of any ocean on Earth). The water temperature is just above freezing. There is no sunlight. The water pressure is an amazing 16,000 pounds per square inch:


4) A "black smoker" off the coast of Washington State. The water churns and boils at more than 200 degrees fahrenheit and is laden with poisonous hydrogen sulfide gas. The ocean depth is approximately 2 kilometers (2000 meters). The water pressure is about 15 x the pressure we experience on the Earth's surface.

5) A massive lake of liquid water more than 10,000 feet below Vostok Station in Antarctica. Temperature 27 degrees farenheit (the pressure of the ice above lowers the freezing point of the water below). Pressure is approximately 5000 pounds per square inch. There is no sunlight:

6) The Atacama desert in Chile is often cited as the dryest non-polar place on Earth. Rain is frequently absent for years at a time. Daytime temperatures range from freezing to approximately 80 degrees farenheit:

7) The Halemaumau fire pit in the Kilauea Crater on the Big Island of Hawaii. Strong concentrations of carbon dioxide, hydrogen sulfide and other poisenous gases. Temperatures reach 1200 degrees celsius (2100 degrees farenheit):



Only one of those (seemingly) hostile environments is absent of life: Halemaumau. The temperature of the lava is just too hot to support any type of life.

However, every other environment DOES support some sort of life....let's go see.



It looks like we need to revamp our understanding for the requirements of life.

Let's try again...


How about this?


  1. Source of Energy
  2. Appropriate Chemical Compounds (although we're not 100% on what those are)
  3. Water
  4. Not TOO Hot (and presumably not too cold, but we're not sure what TOO cold might be)


Here's an interesting (I HOPE) takeaway-- Every place on, in, and above the Earth that we've looked for life, we've found it!