It is 50 years since a man first stepped foot on the moon (20th July 1969). Why go back?
Not long after the moon landings it became apparent that the solar system was a desert. Mars did not have canals and luxuriant vegetation and the clouds of Venus were composed of sulphuric acid and were not harbingers of a steamy vegetative paradise. Despite beautiful pictures of the outer planets and the burgeoning satellite industry the general public lost interest in people actually going into space and exploring it.
The public view is slowly changing. It is now clear that solar systems with planets are very common in our galaxy and over 4000 of these "exoplanets" have been discovered. The panspermia hypothesis that life is transmitted through space has also been going from strength to strength after the discovery of numerous bacteria and archaea in rocks. In fact these tiny organisms, known as endoliths, are surprisingly common. Many can survive extreme temperatures - up to 120 C - and they occupy the top 3 to 4 kms of the earth's crust. The recent Indian (ISRO) discoveries of bacteria 40 km above the earth also favour panspermia. Life on earth can be ejected into space in small rock particles by meteorite impacts or simply leave earth by floating away. If life on earth can be released into space and survive as durable bacterial spores or in rocky space capsules then life could have come to earth in a similar way.
Panspermia is looking increasingly probable. It is even possible that the fossilised remains of endoliths have already been discovered on a meteorite that was blasted from Mars and it is possible that endoliths have been cultured from more recent meteorites.
Life could have seeded the entire solar system but be hidden in rocks several metres below the surface of planets and planetoids. If panspermia occurs life would be the rule throughout the galaxy.
The search for life inside other planets needs manned spaceflight. Drilling a few metres into lunar or martian rocks and then culturing the bacteria extracted from the cores really needs human intervention. We are not going to find definitive evidence of life as easily using automated rovers. If endoliths are found on Mars or the Moon we would be forced to assume that life is ubiquitous across the solar systems of the galaxy.
I suspect that life will be found deep within Mars. If this is the case then we can only wonder. Where are all the extraterrestrials and why haven't they even left their footprints on the moon? There are perhaps hundreds of billions of planets in our galaxy alone so the development of life into something similar to us is highly probable, panspermia or not. Either the solar system is a wildlife park and strictly off limits for physical exploration by aliens or something stops life from developing into tool using entities such as ourselves or perhaps higher intelligences cannot see the point of physical exploration or life has only developed on Earth. I find the first alternative most likely and the least probable option is that life only exists on Earth.
Whatever the truth about aliens it is good to see that NASA has a plan to return to the moon by 2024. This mission will be much cheaper and easier than the Apollo missions, NASA can even buy an off the peg rocket to do the job from Elon Musk's SpaceX.
Not long after the moon landings it became apparent that the solar system was a desert. Mars did not have canals and luxuriant vegetation and the clouds of Venus were composed of sulphuric acid and were not harbingers of a steamy vegetative paradise. Despite beautiful pictures of the outer planets and the burgeoning satellite industry the general public lost interest in people actually going into space and exploring it.
The public view is slowly changing. It is now clear that solar systems with planets are very common in our galaxy and over 4000 of these "exoplanets" have been discovered. The panspermia hypothesis that life is transmitted through space has also been going from strength to strength after the discovery of numerous bacteria and archaea in rocks. In fact these tiny organisms, known as endoliths, are surprisingly common. Many can survive extreme temperatures - up to 120 C - and they occupy the top 3 to 4 kms of the earth's crust. The recent Indian (ISRO) discoveries of bacteria 40 km above the earth also favour panspermia. Life on earth can be ejected into space in small rock particles by meteorite impacts or simply leave earth by floating away. If life on earth can be released into space and survive as durable bacterial spores or in rocky space capsules then life could have come to earth in a similar way.
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| Endoliths - courtesy Carleton College. |
Life could have seeded the entire solar system but be hidden in rocks several metres below the surface of planets and planetoids. If panspermia occurs life would be the rule throughout the galaxy.
The search for life inside other planets needs manned spaceflight. Drilling a few metres into lunar or martian rocks and then culturing the bacteria extracted from the cores really needs human intervention. We are not going to find definitive evidence of life as easily using automated rovers. If endoliths are found on Mars or the Moon we would be forced to assume that life is ubiquitous across the solar systems of the galaxy.
I suspect that life will be found deep within Mars. If this is the case then we can only wonder. Where are all the extraterrestrials and why haven't they even left their footprints on the moon? There are perhaps hundreds of billions of planets in our galaxy alone so the development of life into something similar to us is highly probable, panspermia or not. Either the solar system is a wildlife park and strictly off limits for physical exploration by aliens or something stops life from developing into tool using entities such as ourselves or perhaps higher intelligences cannot see the point of physical exploration or life has only developed on Earth. I find the first alternative most likely and the least probable option is that life only exists on Earth.
Whatever the truth about aliens it is good to see that NASA has a plan to return to the moon by 2024. This mission will be much cheaper and easier than the Apollo missions, NASA can even buy an off the peg rocket to do the job from Elon Musk's SpaceX.
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| A SpaceX re-usable rocket |
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