'Surprising' study finds some planets may be better suited to life than Earth
There may be planets outside of our solar system that host a “greater variety” of life than Earth, according to a group of U.S. scientists.
The new research, which was presented this month at the Goldschmidt Conference in Barcelona, used NASA-developed software to model the likely conditions on various types of exoplanets. They found that some of these planets may have ocean conditions even better suited to life than our own.
“This is a surprising conclusion,” said lead researcher Stephanie Olson of the University of Chicago in a statement. “It shows us that conditions on some exoplanets with favourable ocean circulation patterns could be better suited to support life that is more abundant or more active than life on Earth.”
NASA focuses on “Habitable Zone planets” in their search for other livable worlds. A key condition for livability, among other factors, is that the planet be an appropriate distance from the star it orbits in order for liquid water to be present. “But not all oceans are equally hospitable,” said Olson, whose team worked to define what types of oceans are most conducive to life because of the most “efficient upwelling.”
“Life in Earth's oceans depends on upwelling (upward flow) which returns nutrients from the dark depths of the ocean to the sunlit portions of the ocean where photosynthetic life lives. More upwelling means more nutrient resupply, which means more biological activity. These are the conditions we need to look for on exoplanets,” said Olson. “We found that higher atmospheric density, slower rotation rates, and the presence of continents all yield higher upwelling rates. A further implication is that Earth might not be optimally habitable—and life elsewhere may enjoy a planet that is even more hospitable than our own.”
The closest exoplanet is more than four light years away, making it “effectively impossible” to send space probes to study them, the statement added. Instead, advanced telescope technology will be needed to further understand exoplanets.