Venus is the closest planet to Earth and rotates on its axis in the opposite direction to most planets in the Solar System. Venus is very similar to Earth in size and mass, which is why it is often called “Earth’s sister”. The diameter of Venus is only 650 km smaller than Earth’s, and its mass is equal to 81.5% of Earth’s mass.
However, the conditions there are very different from those on Earth because of the dense atmosphere composed mainly of carbon dioxide, which makes up 96.5% of the atmosphere’s mass, and the remaining 3.5% is mainly nitrogen. The temperature on the planet’s surface is about 500 degrees Celsius. The pressure there is 92 times higher than on our planet. This dense atmosphere makes it impossible to know the planet Venus in more detail.
The surface of Venus is dominated by a volcanic landscape, whose rocks are covered with about a meter layer of volcanic ash. However, scientists are not sure if the planet is still volcanically active. Although our neighboring planet was volcanically active as recently as 2.5 million years ago, no concrete evidence has been found that volcanic eruptions still occur on the surface of Venus.
The discovery that Venus once experienced significant volcanic activity was made in the 1990s by NASA’s Magellan probe. Radar images of Venus’ surface revealed a world dominated by volcanoes and vast lava flows. In 2000, the European Space Agency (ESA) continued the research by measuring the amount of infrared light emitted from the planet’s surface at night using the Venus Express probe. The results of this study shed new light on Venus’ volcanic activity.
The data allowed scientists to study the lava flow on Venus’ surface in more detail and distinguish between old lava and new lava. Unfortunately, the exact age of the lava eruption could not be determined because the rate of change of the fresh lava was not free. A new study by scientists at the Universities Space Research Association (USRA) found that there may still be active volcanoes on Venus. This makes Venus the only planet in the Solar System (other than Earth) where volcanic activity still occurs.
For the study, scientists simulated Venus’ atmosphere in a laboratory to investigate how the flow of lava on Venus would change over time. These simulations showed that olivine (a mineral that is rich in basaltic rock) reacts quickly with an atmosphere similar to that of the planet Venus and would become covered in magnetite and hematite (two minerals that are iron oxide) within a few days. The results of the study suggest that the observations of lava flows made by the Venus Express probe could be only a few years old, which in turn confirms that Venus is volcanically active. These findings may also have implications for our understanding of the internal dynamics of rocky planets such as Earth and Mars.
To study the atmosphere of the planet Venus and the state of its surface, several space missions to the planet are planned in the near future. India’s Shukrayaan-1 orbiter and Russia’s Venera-D spacecraft are currently in development and are scheduled to launch by 2023 and 2026, respectively. These and other missions (which are still in the concept stage) will attempt to solve the mystery of “Earth’s sister planet.”