The changing climate of Venus

According to research, our neighbour’s environment has changed dramatically

STEP 1

Magma ocean

Just like the primitive Earth, early Venus was still largely molten as a result of the high-energy impacts that formed the planet in the first place. This led to a widespread ocean of magma (molten rock) across the planet, leading to very high temperatures.

STEP 2

Gas and steam

Impacts added additional material to Venus, including a significant amount of water. Coupled with the heat from the magma ocean and Venus’ proximity to the Sun, an early atmosphere began to form around the planet, largely made of carbon dioxide and steam.

STEP 3 Cooling and condensing

Over time the number of impacts began to die away; the unbattered planet began to cool down and a solid crust formed on the surface. Steam started to condense out of the atmosphere and fall as rain, creating Venusian lakes, rivers and seas.

STEP 4

Vociferous volcanism

Deep inside the planet, under the crust, the magma ocean persisted. This led to wide-scale volcanism across Venus. Today we can still see these volcanoes, including the planet’s tallest – Maat Mons. Eruptions added huge quantities of carbon dioxide back into the atmosphere.

STEP 5

Global warming

As we’ve discovered on Earth, carbon dioxide is a powerful greenhouse gas. It lets solar energy in, but makes it hard for it to escape. Over time this has raised the temperature on Venus, far beyond the boiling point of water. No lakes, rivers or seas remain.