ACEIZE Tracking the current state of Science and Technology

This is an older article from back in March, 2009. It has been sitting in my ever increasing list of articles to catalog.

There are two major ideas covered by the article. One is Ames Research Laboratory research, Carol Stoker's Habitability Index. The other is the idea that Mars may have harbored some biological life in the past with the implication that Mars has the ingredients needed to support life in the future.

Habitability Index

Stoker said that the current level of knowledge about biology leaves 3 factors which affect the probability of life occurring in a given place.

• The presence of liquid water.
• The presence of a biologically available energy source.
• The presence of the chemical building blocks of life in a biologically available form.

Awkwardly, MSNBC lists a fourth very sensical necessity for life "temperature and water activity must be high enough to support growth."

Basically, the habitability index is a way of boiling down all the above factors into one simple number.

Phoenix Lander, Northern Plains landing site

This habitability index talk brings us back to the Phoenix lander. At the lander's Northern Plains landing site, evidence of water ice and perchlorate salts were found in the soil.

The perchlorate salts are a big deal because the salts are used by microbial organisms for metabolism (ie, convert food to energy).

The presence of ice rich soil and perchlorate salt lead Stoker to conclude that Mars' Northern Plains may presently be periodically capable of sustaining biological activity. Also, the site may have been habitable in modern times. More generally, this area of Mars has the highest habitability index of any site yet explored on the planet.