The Kepler Space Telescope and Transitioning Exoplanet Satellite Survey have allowed scientists to observe previously-unknown worlds orbiting stars in our solar system’s neighborhood. According to a new study, some exoplanets may have better conditions for life than on Earth, based on their location, as well as some other properties.
“This is a surprising conclusion,” lead researcher Dr. Stephanie Olson said 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.”
Since scientists have discovered exoplanets, they’ve intensified their hunt for the right exoplanet, the one with conditions that can harbor life as we know it on Earth. However, while space telescopes help locate the planets using the transit method (searching for dimming stars as their planets transit in front of them), space telescopes can’t be used to conduct in-depth analysis of what those planets contain, other than determining some basic physical properties like mass, size and type, or whether it’s a rocky or a gas planet.
Because of the limitations that come with space telescopes, scientists need to come up with newer models and algorithms that can survey the planetary evolution and climate, which would help scientists determine whether some planets can host life. A new synthesis of this work was presented in a Keynote Lecture at the Goldschmidt Geochemistry Congress at Barcelona.
“NASA’s search for life in the Universe is focused on so-called ‘habitable zone’ planets, which are worlds that have the potential for liquid water oceans,” Olson said. “But not all oceans are equally hospitable—and some oceans will be better places to live than others due to their global circulation patterns.”
Olson’s team used ROCKE-3-D software to search for conditions on different types of planets finding that some may have better conditions for life than Earth. The software was developed by NASA’s Goddard Institute for Space Studies.
Increased life in oceans depends on upward flow (upwelling), resupplying more nutrients from below to the surface where photosynthetic life lives.
They have modeled a great variety of exoplanets determining which of those may support better conditions for life than on Earth.
“We have used an ocean circulation model to identify which planets will have the most efficient upwelling and thus offer particularly hospitable oceans,” Olson said. “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.”
Olson added that there will always be some limitations with the currently-available technology, which shows that life is “almost certainly more common than ‘detectable’ life.” Scientists aim to target exoplanets that have the visible properties of a habitable planet, that it’s large, and has rich and active biospheres, because with such planets they will have the best chance of detecting potential extraterrestrial life.