At present the only planet or moon that is known to support life in The Solar System is Earth. It is not to say that life can`t and doesn`t exist on other planets and moons, its just we`ve not finished checking everywhere yet. There are eight planets and an untold number of moons that have to be checked.
Mercury, the closest planet to The Sun, is far too hot to support any life. It may have a thin atmosphere of oxygen but the heat from the Sun would vapourise and prevent any life forms from forming. It is safe to say that there is no life on the planet. There might be life forms deep under ground but that is highly unlikely.
Venus was once thought to contain life especially as it was near our planet and within the goldilocks zone which Earth is also in. The goldilocks zone is the area of space that not too far and not too near the Sun for life to exist. Eagle comics in United Kingdom had a race of aliens known as the Treen in the Dan Dare stories that hid under the thick atmosphere. When space probes primarily from Russia or as it was known then, the Soviet Union sent Venera probes to the planet, they discovered that the planet was hot and a sulphuric atmosphere, one in which no life could exist because it was too toxic.
However, on Earth, life has been known to exist in the most extreme of locations, near hot spurs under water but the atmosphere it too toxic at ground level. The pressure in the atmosphere would prevent anything from starting. There is a possibility that life forms, bacterial could life high in the atmosphere, at the very edge where the atmosphere is may just be right to support life. Niether Venus nor Mercury have any moons which could support life.
This, the third planet from the Sun, our home in the Solar System is the only planet that can at present support life naturally. Earth has the right ingredients and is sufficiently far away from the Sun to be able to just the right temperature to support life. At present there are seven billion humans and an untold number of less intelligent animals and possibly trillions of other lifeforms including dogs, cats and Micro-Organisms. Micro-organisms include viruses and bacteria, however it depends on whether you class them as life. the moon has no atmosphere and therefore no life could ever exist on the planet. Whilst the moon was created by a planetoid smashing into the early Earth, life was not thought to have existed at the time of the smash and so no viral pollution would`ve ended up on the Moon.
There has always been speculation as to whether there is life on Mars or whether there had and no longer is life on Mars. The planet has featured as the home of a warrior race for hundred of years who wish to conquer the Earth such as in War of the Worlds by H.G. Wells. In Mars Attacks, the Martians lived underground whilst they plotted their conquest of our planet. We`ve been sending probes to the planet for tens of years but haven`t found any concrete evidence. The best evidence of life that scientists are hoping for is bacterial life forms. As mentioned previously, bacteria on Earth have been found in the most extreme of locations. Even though the probes that are sent to outer space are sterialised to ensure that they don`t contain hitch-hiking bacteria, it is not 100% fail proof and Earth bacteria could in the most extremely rare case survive on the planet. The planet has ice caps on its north and south poles, bacterial could be encassed inside them.
One theory is that life did take off on Mars but lost its ability to support life. On Earth, we have a magnetic field that protects us from the Sun`s radiation however on Mars, its shielding has disappeared and therefore advanced life would be killed off on the planet. There is a new race between the nations to get a community on Mars but we would need to build living quarters that would shield us from the Suns power, not an easy thing to do. Kim Stanley Robinson wrote about a trilogy of books (Red Mars, Green Mars, Blue Mars) about setting up on Mars and terraforming the planet. Terraforming the planet would be hinhibitively expensive and whether it could be done would need to be answered.
iMars is not in the goldilocks zone but one day, the Sun will start to expand and the goldilocks zone will move out further than it is and Mars will one day be in that zone. Humans wishing to survive will move to that planet before having to move again when the Sun expands further. Hopefully before we have to move from Earth or Mars, we will have created faster than light travel and have left the Solar System, having set up on an Extrasolar Planet. An extrasolar planet is a planet doesn`t orbit our Sun but orbits a star somewhere else in the Galaxy.
The asteroid belt contains hundreds and hundreds of rocky object, none of which could contain life. The rocks are belived to have been debris that couldn`t form into a rocky planet because of the influence of Jupiter, the largest planet in our solar system. The largest object is Ceres, now classified as a dwarf planet. Scientists now believe there is water vapour on the planetoid but not life. Ref:Sci-News. The chances of any life on any object within the asteroid belt is low, next to zero.
Jupiter is the largest planet in the solar system, some theorized it is a failed star that didn`t have enough energy or mass to become a star. It is thought to have a small rocky core but nothing able to support life. The atmosphere has high pressure and anything would be crushed to a pea by the strength of the gravity on the planet. The best chance of life existing here would be on a moon that is in orbit around the planet.
Ganymede is the biggest moon in the solar system, it is even bigger than the planet Mercury. Oxygen has been discovered in the atmosphere on the planet. It like Europa has an icy exteior but underneath the ice could be water if the planet core is hot enough to allow water to free flow. ref:Discovery
Europa is long seen as being a possibly moon that could support life forms. It has a icy crust which plumes of steam have been seen shooting out of its exterior. In 2001, a space odyssey, Europa is the planet where Earth is told to avoid but they could visit every other planet and moon in the solar system. The planet is covered in a thick icy crust but under the crust, it is believed there could be free flowing water. it is one of the most likely candidates for life to exist on other than the Earth. Future N.A.S.A. science missions are being planned to visit the moon to study it. The first voyage to the planet would be to survey the planet from a satiellite with ice penetrators. Later missions would be to break the crust and send down a probe. Sending a probe into the ice crust does open possible ethical questions as we might be introducing a virus to their ecosystem which would klll the life forms off. An example of this is that when Europeans went to the Americas, they introduced unwittingly diseases which the natives had no natural resistence to. One of the things that life needs is heat and heat is generated on Europa by the gravity of Jupiter which causes the planet to expand and contract. Ref:Caltech
Saturn is the second largest planet in the solar system, the first being Jupiter. Saturn is famous for its rings which all four gas giants have but the rings on Saturn are more prominent than the other planets. Like Jupiter, being a gas planet, it is unlikely to have a rocky core. It doesn`t have a breathable atmosphere unlike Bespin, the gas giant in Star Wars. The rings are made up of rocks and ice and neither of those would be sufficient to support life. The most likey place to find life is on the atmospheric moon of Titan.
Although its name might create the impression it is the biggest, Ganymede is still bigger than Titan. The moon is the only moon in the solar system with an atmosphere. NASA/ESA/Italian Space Agency sent Cassini-Huygens Spacecraft to the moon in the nineties to investigate the planet. The space probe was two parts, one was parachuted down to the planet. The project is still in progress but no reports of life has been reported yet. Cassini mission was not equiped with equipment to search for organic compounds so it is unlikely anything will be found as part of the mission. Ref:Wiki. According to ESA, there has been methane discovered in the atmosphere which is destroyed by sunlight but the quantities of methane that exists on the planet must indicate it is being regenerated by something else. Methane on Earth is a byproduct of organic life. Ref:E.S.A.
The Saturnian moon of Enceladus is being hailed as the most likely place in the solar system to have life other than Earth. According to press reports in early April 2017, N.A.S.A believes this could be the place to look further. The moon is ice covered but under the ice, they believe there could be free water. Where there`s water, there could be life. Further analysis of the planet needs to be carried out, another probe would need to be sent to carry out the necessary experiments needed. Ref: BBC
Uranus is a gas giant with like the other planets has a large number of moons. The planet itself would not be able to support life as there is no surface and it has a high pressure atmosphere. It would also been too far from the Sun. According to universe Today, life could possibly but unlikely exist on the planet. The planet has an atmosphere of Hydrogen and Helium but more importantly Methane. Ref:Universe Today. Methane would have needed to have been produced somehow but probably not through the same way as it is on Earth. Uranus is also cold and well outside the Goldilocks Zone.
At present due to the International Astronomical Union (IAU) downgrading the planet Pluto to dwarf planet, Neptune is currently the furthest planet from the Sun and the Earth for that matter as well. Neptune is a large gas giant, blue in colour and with an untold number of moons. Whilst this site might detail 14 of its moons, they`ll be quite a few more, some undiscovered.
Back to the planet at hand, the planet won`t have a solid sturface like that of Earth or Mars, it will most likely have a rocky core, not one on which life could exist on. The atmosphere would be heavy pressure and anthing if anything would need to have a strong body to withstand. The atmosphere contains methane which on Earth is a by-product of organic material so extremely possible something living could have created it. Like with all the other gas giants, if anything does live there, it would be microscopic organisms. Ref:Mysterious Universe
Up until the mid-noughties, Pluto was classified as a planet, it was downgraded after a vote by the I.A.U. What prompted the downgrading was the discovery of Eris, an object that was bigger than Pluto. Unlike the other outer planets, Pluto is a rocky planet like Mercury. Not much is known about Pluto as it is so far away. N.A.S.A. sent the New Horizons space probe out to study it for the first time. It is so far from the Sun, the Sun is nothing more than a dot. Pluto is far too cold to allow for water to be free flowing on the planet. Unlike one of its moons Charon, it next to zero of finding life on the planet.
Charon is the biggest moon of the dwarf planet Pluto. According to NASA scientists, there is a remote chance that the moon could contain life under its icy crust. According to scientists analyzing the moon, they have said that cracks on the surface of the frozen moon say it points to the existence of strong, warm, tidal oceans beneath. As the discovery is new, the New Horizons craft would not have been kitted out with equipment to check for any possible life on the moon. Ref:Daily Mail
The one time tenth planet provisionally called Xena after the Warrior Princess television character is so far away from Earth that we don`t know much about the dwarf planet. The only thing we do know is that its about the same size of the planet Pluto. The only observations we have of the planet and its moon is from Earth based telescopes. At the moment, nothing is being sent out towards the planet. It is too far away from Pluto for the New Horizons to be redirected to it. The atmosphere at present is said to contain methane which could indicate a slight chance. The inner core of the planet could be heated from the core. Ref:Mysterious Universe.
Sedna is one of the furthest objects in our solar system. Technically it is not part of the Solar System because it is so far from Pluto that it is intergalactic space. For any life to exist, the life would need to be not dependant on solar power and the planetoid must be able to generate its own heat source from within. Unless we get faster than light travel, there is no change of any space probe visiting the planet.
There is only one confirmed location at the moment that contains life presently and that is our home, planet Earth. Unless there is free flowing underwater activity on some of the moons in our solar system, the only life forms that we could possibly find elsewhere is bacterial. One day, we might get to Mars and discover that life once did exist but when the planet died, life died toon. On Earth, high in the sky, talking cloud levels, micro-bacterial life has been discovered to exist which raises the possibility that life could exist on gas giants and Venus. The most likely place for life existing is on extrasolar planets.
|Marco||Monday, 27th March 2017 2:07:39 AM|
|Why is it that life could not live within the gas planets? In other words, how do we know that the gas atmosphere is not concealing an interior that supports some kind of life? Has anybody confirmed there is no ground to walk on underneath that gas? Is it possible the gas acts for the living on that planet as oxygen works for us? I know this is kind of far fetched but I think our biggest setback is that we cannot seem to get our brains to think outside the box. I believe whatever intelligent life we do find will be completely different than us and their life will require completely different "ingredients" than us, like icy cold atmospheres per se|