What makes a world habitable What makes a

What makes a world habitable?

What makes a world habitable? � What makes a place habitable? � Think of life forms and what they need to survive here on Earth. � REMEMBER… life comes in all shapes and sizes… from a tiny microbe, to a human being � In your group, come up with 5 things that a world needs to have in order for life to exist there

What makes a world habitable? Temperature 2. Liquid water 3. Atmosphere 4. Energy 5. Nutrients 1.

1. Temperature 0 to 120 ºF (20 to 50 ºC) � High temperatures breakdown DNA � Low temperatures slow down metabolism �

Lut Desert, Iran � Hottest inhabited place on Earth at 159 °F (71 °C)

Oymyakon, Russia � The coldest inhabited place on Earth � -46 °C (-51 °F) average

-42 °F

2. Liquid Water � All living organisms require LIQUID water � Between 35 and 100 ºF (2 to 38 ºC)

3. Atmosphere Protection from Meteorite impacts � Greenhouse gases � � � Keep heat in Ozone Layer � Protection from UV radiation

Greenhouse Gases � Too many = too hot � Too few = too cold

4. Energy � Light or chemical energy is needed for life processes › Photosynthesis is the main way energy enters ecosystems

5. Nutrients �A constant supply is needed for life � Processes that provide nutrients › Matter Cycles › Volcanoes › Earthquakes