From “Planets’ life-hosting potential ranked” (CBC News, Nov 24, 2011), we learn,
Plugging in parameters such as a planet’s mass, radius, and average temperature generates a series of measures in the Earth Similarity Index, which “provides a quick screening tool with which to detect exoplanets most similar to Earth,” said Dirk Schulze-Makuch, an astrobiologist at Washington State University in Pullman, Wash., in a statement.
He added that scientists know empirically that Earth-like conditions can support life.
Amazing! How did they figure that out?!!
But the researchers noted that some conditions that aren’t Earth-like — such as those found in oily lakes on Titan, a moon of Saturn — could theoretically also be conducive to life — albeit not the kind we are most familiar with.
So how much weight should be given to “theoretically” vs., um, biomass?
The proposed Planetary Habitability Index suggests that we should look for the stuff we find on Earth with the caveat that maybe that stuff’s not necessary after all.
This sentence tells us pretty much everything:
The only known planet or moon either inside or outside our solar system that is truly “Earth-like” using the Earth Similarity Index was found to be Gliese 581g, a planet announced discovered in 2010 that other researchers have since suggested does not exist, based on a reanalysis of the data.
You really have to read the rest for yourself here.
Surely, astrobiology currently meets Lakatos’ criteria for a degenerate research program. If it were a healthy field, they’d be far more content to wait for actual data.
No wonder the article is unbylined. Thoughts?