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Why is Venus too hot to have liquid water on its surface?

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Habitable zone The habitable zones (green) for stars that are like the Sun (middle), hotter than the Sun (top), and cooler than the Sun (bottom). The red areas are those in which liquid surface water would be lost as a result of a runaway greenhouse effect, and the blue areas are those in which liquid surface water would be completely frozen.

Venus is too hot to support liquid water on its surface primarily due to an extreme greenhouse effect caused by its thick carbon dioxide atmosphere.12

While Venus is closer to the Sun than Earth, it actually absorbs less sunlight because its dense cloud cover reflects a significant portion of incoming solar radiation. However, the sunlight that does penetrate the atmosphere is absorbed by the surface and lower atmosphere and reradiated as infrared radiation. On Earth, much of this heat escapes back into space, but on Venus, the massive carbon dioxide atmosphere and thick clouds trap this radiation. This process creates intense surface temperatures of approximately 482 °C (900 °F), which are hot enough to melt lead.12

In the context of astrobiology, Venus is considered to be beyond the inner boundary of the habitable zone. This boundary is defined by the point where a runaway greenhouse effect causes a planet's surface water to boil away and be lost.3