Possible places for extraterrestrial life in the solar system

VENUS – the second planet from the Sun

Pros

• Earth-like in size. The distance from the Sun is appropriate (it is on the border of the habitable zone)
• The existence of chemicals that make up life as we know it.
• It was similar to Earth in many ways in the long past. It is possible that there was an ocean on Venus.
• At a height of about 50 kilometers above the ground, the conditions are theoretically suitable for life as we know it.

Cons

• There is no evidence for the existence of water.
• The surface is suffocating and hot. Temperature 462 degrees C.
• Extreme atmospheric pressure, 92 times greater than sea level pressure on Earth.

MARS – the fourth planet from the Sun

Pros

• Hints that there is still liquid water on the surface.
• Clear signs of the existence of organic building blocks: carbon, hydrogen, phosphorus and nitrogen.
• Richer and denser atmosphere in the past.

Cons

• No traces of extinct life have been found
• The water found in the soil is bound to minerals and is unavailable.
• Very thin atmosphere

TITAN – Saturn’s satellite

Pros

• A dense atmosphere, similar to the Earth’s atmosphere at the time when life arose on it.
• There is methane in the atmosphere. On Earth, methane is largely a product of life.

Cons

• An extremely cold world.

ENCELADS – Saturn’s satellite

Pros

• Tidal forces and external stresses under the influence of Saturn – which can generate heat.
• Jets of water erupting on the surface, indicating the existence of an ocean of water.

Cons

• Extremely cold world.

EUROPA – Jupiter’s satellite

Pros

• Ice on the surface and liquid water below it.
• Jupiter’s tidal forces heat the ocean beneath the satellite’s surface.
• Volcanic activity provides the heat and chemical building blocks needed for life.

Cons

• Lots of unknowns. This satellite has yet to be investigated in more detail.

JO – Jupiter’s satellite

Pros

• Volcanic activity.
• Theoretically, there is a chance that life once existed on this satellite, but it has since retreated underground because of the geothermal activity on the surface.

Cons

• It is located inside Jupiter’s magnetic field. It receives large amounts of radiation.
• Some areas are incredibly cold.
• Some areas are incredibly warm.
• No water found yet.

CERES – dwarf planet

Pros

• Observed water vapors.
• Signs of the presence of a large amount of ice.
• Lighter materials are found on the surface of Ceres, and heavier in the center – a great similarity to Earth.

Cons

• Still a largely unexplored world, knowledge about it still needs to be collected.