Life thrives at stable temperatures. On Earth, this is facilitated by the carbon cycle. Scientists from SRON, VU and RUG have now developed a model that predicts whether exoplanets have a carbon cycle, given the mass, core size and amount of CO2 familiar. Post in Astronomy and astrophysics on May 3.
In the search for life on planets outside our solar system, astronomers do not have the luxury of taking pictures to see what is happening there. Current telescopes do not have the necessary spatial resolution for this; the exoplanets are just too small and too far away. However, the planet̵
Scientists from SRON, VU and RUG have now developed a model that combines the mass and size of the exoplanet’s core with the amount of CO2 in its atmosphere, provided that there is a carbon cycle. So when we quantify these three factors for an exoplanet using a telescope, the model tells us if there is a carbon cycle. The mass and size of the planet’s core are a factor due to their strong effect on plate tectonics, which plays a key role in the carbon cycle.
The carbon cycle has a softening effect on temperature changes as the planet absorbs more CO2 when it gets warmer, which leads to less greenhouse effect. When it cools, the opposite happens. The first step in the cycle is weathering: the rocks react with CO2 and rainwater to form bicarbonate (HCO3). This is deposited on the seabed as a sedimentary rock (CaCO3), while a small amount of carbon dissolves as a residual product in seawater. The plate tectonics then transports the sedimentary rock to the Earth’s mantle. The volcanoes then release CO2 from the sedimentary rock back into the atmosphere.
“We don’t know if there are any other planets with plate tectonics and carbon cycles,” said Mark Osterlu, lead author. “In our solar system, Earth is the only planet on which 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.”
A new idea of 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 from Earth-like exoplanets”, Astronomy and astrophysics, 2021.
Provided by the Dutch Space Research Institute SRON
Quote: The new model can predict the presence of a carbon cycle of exoplanets (2021, May 3), extracted on May 4, 2021 from https://phys.org/news/2021-04-carbon-presence-exoplanets.html
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