Venus Tops 900 F, Outheating Mercury by 100 F on Dense CO2 Blanket
Updated
Updated · Livescience.com · Sep 12
Venus Tops 900 F, Outheating Mercury by 100 F on Dense CO2 Blanket
3 articles · Updated · Livescience.com · Sep 12
Summary
Venus reaches about 900 F, roughly 100 F hotter than Mercury’s peak 800 F, even though it sits 31 million miles farther from the sun.
A carbon-dioxide atmosphere about 90 times denser than Earth’s traps infrared heat on Venus, while Mercury’s near-airless surface sheds warmth quickly after sunset.
Mercury’s temperatures swing from 800 F by day to minus 290 F at night, but Venus stays nearly uniformly hot because its thick atmosphere keeps reabsorbing and reradiating heat.
Venus reflects about three-quarters of incoming sunlight, and only around 3% reaches the surface; stripped of its clouds and atmosphere, bare-rock Venus would be cooler than Mercury.
Scientists say volcanic and tectonic activity likely built that greenhouse blanket, leaving Venus in a post-runaway greenhouse state that shows distance from the sun alone does not determine planetary climate.