Welcome back! We are now half-way through the solar system in our search for the possibility of life in space apart from our home Earth. Let’s continue our journey! We will have a look at planets of Solar system like Jupiter, Saturn etc and also their moons.
Read also: Life in and beyond the solar system? Imagining the possibility– Part 1
Jupiter
Ganymede (Jupiter’s largest Moon)
Europa (one of Jupiter’s smaller moons)
Saturn
Titan (one of Saturn’s moons)
Enceladus (a moon of Saturn)
Uranus
Uranus like Saturn and Jupiter is a gas giant and thus cannot support life due to its toxicity and high-pressure atmosphere. It has an atmosphere of Hydrogen and Helium, but since it is too far from the Sun, it is too cold to breed life.
Neptune
Pluto
Charon (one of Pluto’s moons)
Eris
Sedna
List of potentially habitable exoplanets beyond the solar system
In astronomy and astrobiology, the circumstellar habitable zone (CHZ or sometimes “ecosphere”, “liquid-water belt”, “HZ”, “life zone” or “Goldilocks zone”) is the region around a star where a planet with sufficient atmospheric pressure can maintain liquid water on its surface.
A potentially habitable planet implies a terrestrial planet within the circumstellar habitable zone and with conditions roughly comparable to those of Earth (i.e. an Earth analogue) and thus potentially favourable to Earth-like life. However, the question of what makes a planet habitable is much more complex than having a planet located at the right distance from its host star so that water can be liquid on its surface: various geophysical and geodynamical aspects, the radiation, and the host star’s plasma environment can influence the evolution of planets and life if it originated.
In November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way, 11 billion of which may be orbiting Sun-like stars. – Source: Wikipedia
Here is a list of the exoplanets (extrasolar planets) that are more likely to be able to sustain life. Please note that research is ongoing to ascertain whether these planets can actually support the life of any kind or not. An extra-solar planet is a planet doesn’t orbit our Sun but orbits a star somewhere else in the universe within the vast cosmos.
List of exoplanets in the conservative habitable zone (are more likely to have a rocky composition)
- Proxima Centauri b
- Gliese 667 Cc
- Kepler-442b
- Kepler-452b
- Wolf 1061c
- Kepler-1229b
- Kapteyn b*
- Kepler-62f
- Kepler-186f
- Luyten b
- TRAPPIST-1d
- TRAPPIST-1e
- TRAPPIST-1f
- TRAPPIST-1g
- LHS 1140 b
- Kepler-1638b
List of exoplanets in the optimistic habitable zone (are less likely to have a rocky composition or maintain surface liquid water)
- Kepler-438b
- Kepler-296e
- Kepler-62e
- Gliese 832 c
- K2-3d
- Kepler-1544b
- Kepler-283c
- Tau Ceti e*
- Gliese 180 c
- Kepler-440b
- Gliese 180 b
- HD 40307 g
- Gliese 163 c
- K2-18b
- Kepler-61b
- Kepler-443b
- Kepler-22b
- Gliese 422 b*
- K2-9b
- Gliese 3293 c
- Kepler-298d
- Kepler-174d
- Kepler-296f
- Gliese 682 c
- KOI-4427 b*
- Kepler-1090b
- Ross 128 b
- HD 20794 e*
- Gliese 625 b
- HD 219134 g*
* represents an unconfirmed planet or planet candidate.
Conclusion
Currently, there is only one confirmed location at the moment that contains life and that is our very own home planet, Earth! Yes, we may inhabit other planets like mars someday and discover life forms there, but since Mars is itself a dead planet, chances of finding life there are very, very slim! On Earth, only micro-bacterial life has been discovered to exist at very high altitudes, but it doesn’t rule out the possibility that life could exist on gas giants and Venus. Exo-planets are currently the most likely place for life to exist in the Universe, but to get there, we would have to build freakishly fast spacecraft to make us reach there.
Until then, Earth has the right ingredients to support life, but with a massive seven billion humans and an untold number of other organisms inhabiting it, the planet is choking to its eventual death due to excessive pollution. We need to protect our home planet first before we even plan to colonize other areas in the cosmos!We better start conserving our resources here before it is too late and Earth dies a slow death.