Why is Venus so hot? The planet’s thick CO2-filled atmosphere is great at trapping heat. This creates a runaway greenhouse effect that makes Venus roughly 700°F (389°C) hotter than it would be otherwise. NASA Jet Propulsion Laboratory’s Dr. Amy Hofmann provides all the sizzling details. Explore more about Earth’s closest planetary neighbor: https://go.nasa.gov/42FxR4v | NASA - National Aeronautics and Space Administration