U.S. scientists have come up with two new tools to determine which moons and planets in the universe are most likely to harbour alien life.
And they have used those tools to rank many other planets and moons in the solar system, as well as some planets in other parts of the universe. Their results are published in the journal Astrobiology.
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.
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.
In order to flag planets with those types of conditions, the scientists came up with the Planetary Habitability Index, which assumes a more general set of conditions are needed for life:
A stable and protected substrate, but not necessarily the rocky surface found on Earth.
Energy, although the main source doesn't need to be light from a Sun-like star.
Chemistry that allows large, chain-like molecules to be built, but not necessarily the carbon-based chemistry on Earth.
A liquid medium, but not necessarily water.
"The disadvantage of this approach is that it is intrinsically more speculative," the researchers wrote. "The alternative, however, to miss habitable worlds due to restricted assumptions would be self-defeating."
Continued here: http://www.cbc.ca/news/technology/story ... -life.html
Care to speculate on what kind of substrate, energy, Chemistry and liquid medium that would entail? I'm quite interested in this.And they have used those tools to rank many other planets and moons in the solar system, as well as some planets in other parts of the universe. Their results are published in the journal Astrobiology.
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.
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.
In order to flag planets with those types of conditions, the scientists came up with the Planetary Habitability Index, which assumes a more general set of conditions are needed for life:
A stable and protected substrate, but not necessarily the rocky surface found on Earth.
Energy, although the main source doesn't need to be light from a Sun-like star.
Chemistry that allows large, chain-like molecules to be built, but not necessarily the carbon-based chemistry on Earth.
A liquid medium, but not necessarily water.
"The disadvantage of this approach is that it is intrinsically more speculative," the researchers wrote. "The alternative, however, to miss habitable worlds due to restricted assumptions would be self-defeating."
Continued here: http://www.cbc.ca/news/technology/story ... -life.html
