Life thrives at stable temperatures. On Earth, this facilitates the carbon cycle. Researchers at SRON, VU and RUG have now developed a model that predicts whether a carbon cycle is present on exoplanets, assuming the mass, core size and amount of CO2 is known. Publication in Astronomy and astrophysics on May 3rd.
In the search for life on planets outside our solar system, astronomers do not have the luxury of taking pictures to see what is going on out there. Current telescopes do not have near the required spatial resolution for this; exoplanets are simply too small and too far away. However, a planet̵
Researchers at SRON, VU and RUG have now developed a model that links the mass and core size of an exoplanet to the amount of CO2 in its atmosphere, provided there is a carbon cycle. So when we quantify these three factors for an exoplanet using a telescope, the model tells us if it has a carbon cycle. The mass and core size of a planet are a factor due to their strong effect on plate tectonics, which play a key role in the carbon cycle.
The carbon cycle has a dampening effect on temperature changes because a planet absorbs more CO2 when it gets warmer, leading to less greenhouse effect. When it gets cooler, the opposite happens. The first step in the cycle is weathering: rocks react with CO2 and rainwater to form bicarbonate (HCO)3). This is deposited on the seabed as sedimentary rock (CaCO)3), while a small part of the carbon is dissolved as a residual product in the seawater. Plate tectonics then transports sedimentary rock to the Earth’s mantle. Next, volcanoes release CO2 from the sedimentary rock back to the atmosphere.
“We do not know if there are other planets with plate tectonics and a carbon cycle at all,” says Mark Oosterloo, lead author of the newspaper. “In our solar system, Earth is the only planet where we have found a carbon cycle. We hope that our model can contribute to the discovery of an exoplanet with a carbon cycle and therefore possibly life.”
New insights into the Earth’s carbon cycle
M. Oosterloo, D. Höning, IEE Kamp and FFS van der Tak, ‘The role of the planetary interior in the long-term evolution of atmospheric CO2 on Earth-like exoplanets’, Astronomy and astrophysics, 2021.
Provided by SRON Netherlands Institute for Space Research
Citation: New model can predict the presence of carbon cycle on exoplanets (2021, May 3) retrieved May 4, 2021 from https://phys.org/news/2021-04-carbon-presence-exoplanets.html
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