Monica Grady, a professor of planetary and space science and the chancellor at Liverpool Hope University has claimed that extraterrestrial living beings might be thriving beneath the ice sheet in Jupiter's moon Europa.

She also talked about the possibility of life on Mars but made it clear that possible extraterrestrial presence on the Red Planet will be under the surface of Mars.

Extraterrestrial life on the Solar System

salt found on Europa
Tara Regio is the yellowish area to left of center, in this NASA Galileo image of Europa’s surface, where researchers identified abundant sodium chloride NASA/JPL/University of Arizona

"When it comes to the prospects of life beyond Earth, it's almost a racing certainty that there's life beneath the ice on Europa. Elsewhere, if there's going to be life on Mars, it's going to be under the surface of the planet... There you're protected from solar radiation. And that means there's the possibility of ice remaining in the pores of the rocks, which could act as a source of water," said Grady in a recent statement.

However, Grady added that the possibility of discovering complex life forms will be more likely on Europa than on Mars. Grady believes that Europa is the most alien-friendly locale in the solar system, and in Europa, it may be possible to discover higher forms of alien life similar to the intelligence of an octopus.

It should be noted that several previous observations have suggested the salty nature of water under the ice sheets in Europa. Apart from this, water is heated by hydrothermal vents which creates a nice condition for living beings to thrive.

What humans will discover on Mars?

As per Grady, if alien life is going to be discovered on Mars, it will be in bacterial form. "If there is something on Mars, it's likely to be very small - bacteria. I'm fairly certain we're all there is at our level of intelligence in this planetary system," added Grady.

Interestingly, Dr Jim Green, a NASA chief scientist had also suggested that alien life will be discovered on Mars within 2021 by either NASA or ESA. However, Green also revealed that humans are not prepared enough to accept the realities surrounding extraterrestrial existence.