If Venus had an atmosphere similar to Earth’s, its surface temperature would be significantly cooler than it is with its current thick and dense atmosphere, which is mostly composed of carbon dioxide. The extremely hot surface temperatures on Venus, which can reach over 900 degrees Fahrenheit (475 degrees Celsius), are primarily due to the planet’s thick carbon dioxide-rich atmosphere, which creates a potent greenhouse effect.

In contrast, Earth’s atmosphere is composed mainly of nitrogen and oxygen, with a relatively low concentration of carbon dioxide. This composition allows Earth’s atmosphere to regulate temperature through the greenhouse effect, which involves trapping some of the sun’s energy, keeping the planet warm enough to support life but not excessively hot.

If Venus had an Earth-like atmosphere, it would have a milder greenhouse effect, which would result in more moderate surface temperatures. The exact temperature would depend on various factors, including the composition of the atmosphere and the planet’s distance from the sun.

In essence, if Venus had an atmosphere similar to Earth’s, its surface temperature would be considerably cooler and might even support conditions conducive to liquid water, a crucial element for the possibility of life as we know it. However, other factors, such as Venus’s proximity to the sun and its lack of a magnetic field, would still present challenges for habitability.