Astronomy
The Geochemical Cycles That Shape Venus's Surface and Atmosphere
Quick fact
Venus's atmosphere-surface reactions release carbon dioxide, but it's the planet's extreme heat and lack of water that prevent the carbon from being locked back into the rocks. This shattered the planet's natural thermostat, cooking it in a runaway greenhouse effect.
Why this is interesting
On Venus, a simple process like the weathering of rocks doesn't cool the planet down—it actively pumps more greenhouse gas into the sky. How can the planet's own surface be making its atmosphere even more hellish?