The Voyagers

by Peter Jekel

If the radiance of a thousand suns

Were to burst forth at once into the sky

That would be like the splendor of the Mighty One

I am become Death

The shatterer of worlds.

Bhagavad Gita

Is life indigenous to the planet Earth or did it come from somewhere else? Could it be that are we truly aliens that originally visited in the guise of organic chemicals and possibly even microbes that evolved and eventually colonized this beautiful planet of ours? The first mention of this possibility was Greek philosopher, Anaxagoras, in the fifth century B. C. In the nineteenth century, several preeminent scientists such as English physicist Lord Kelvin, Swedish chemist Jons Jacob Berzelius and German physician/physicist Hermann von Helmholtz suggested that there is a process whereby life was able to plant itself from one world to another. The process is known as panspermia; that is, that life arose on Earth and on other planets via a system of transfer from outer space.

Ideas abound as to how this transfer takes place. Late nineteenth century Swedish chemist Svante Arrhenius in an article written in 1903 entitled The Distribution of Life in Space, suggested that life arrived on Earth in the form of spores, pushed here by radiation pressure.

Panspermia has been dismissed by many scientists. One scientist, more famous as a science fiction writer, Isaac Asimov, contended that the theory was not worth consideration. Yet the theory does have a number of heavyweight supporters. Francis Crick of Watson and Crick fame (discoverers of the DNA molecular shape) believed that an alien race is responsible for the transfer of life onto our planet. In fact, in his book, Life Itself, he describes the type of spacecraft needed to seed the planets. Sir Frederick Hoyle, the late British astronomer who is ironically credited with the naming of the “Big Bang Theory” origin of the universe while at the same time advocating for the contradicting Continuous Creation Theory, believed that life was transferred to our planet on comets. Later Hoyle and Wickramsinghe proposed that it is possible that outbreaks such as influenza and other epidemics actually have outer space origins.

A number of experiments have shown that bacterial spores if exposed to the true vacuum of space will be destroyed, but if there is any protection such as being embedded in clay or artificial meteorites, spores are capable of amazing feats of survival.

There has also been some accidental demonstrations of the survivability of bacteria in outer space. NASA’s Surveyor 3 landed on the Moon on April 20, 1967 and remained in place on the Moon until Apollo 12 which landed on November 19, 1969 in the vicinity of the landing site of the earlier spacecraft. One of the tasks of Apollo 12 astronauts was to collect parts of the Surveyor spacecraft to return to Earth for study of the long-term effects of the lunar environment on human technology. The findings were nothing short of amazing. Embedded within the camera was a colony of Streptococcus mitis, a common Earth bacteria. It had survived the vacuum of space, radiation and temperature extremes of the lunar surface, in a camera housing for over three years. Though some scientists contended that the contamination was more recent, it did not stop NASA from initiating very strict protocols to prevent the contamination of extraterrestrial worlds. In fact, the crashing of the Galileo spacecraft into Jupiter was intentional to prevent the possible contamination of Europa by earthly bacteria. Similarly, NASA also crash-landed the Cassini space probe into the parent planet, Saturn, to prevent the possible contamination of one of the planet’s fascinating and possibly life-baring moons.

There is another form of more likely panspermia known as pseudo-panspermia which involves the transfer of the building blocks of life to other worlds. Once on those planetary surfaces, the process of chemical and eventually life evolution takes over. It was Sir Frederick Hoyle and Chandra Wickramsinghe who first showed that interstellar molecules are formed by chemical reactions in the interstellar clouds of dust and clouds. In fact, they contended that the near absolute zero temperature of space within hydrogen clouds provided ideal conditions for the creation of life, far better than the violence of an early Earth.

Hoyle and Wickramsinghe were dismissed when they first proposed their ideas, but increasingly evidence mounted that they were indeed correct, that the cosmos was a place in which complex organic compounds could be found. In 2008, organic compounds were found in the Murchison meteorite which had landed in 1969 in Australia. Within the meteorite, over fifteen amino acids were found. In August 2012, astronomers at Copenhagen University reported that they found a sugar molecule in a distant star system. In September 2012, NASA reported that polycyclic aromatic compounds are transformed after exposure to interstellar conditions into complex organics. Then, in 2013, researchers reported that they had found a pair of prebiotic molecules in icy particles of outer space. As our instrumentation to detect chemicals in the cold depths of space has increased so has the frequency of the discovery of organic chemicals in space.

We see that organics are found in the frozen reaches of outer space, but how do they arrive on Earth? One way is through the destructive power of a comet. The word “comet” comes from the Greek, meaning “hairy star” which is a perfect description. To an earthbound person that is exactly what they look like.

Comets are fragile extraterrestrial bodies made up of ices such as carbon dioxide, ammonia, methane, carbon monoxide and water as well as a dusting of silicates and a sparse sampling of metals. Their orbits are generally highly elliptical with orbital periods that range from a few years to several million years. The most famous comet of all is Halley’s Comet which was the first comet whose orbit was predicted in 1705 by English astronomer Edmond Halley. A number of writers have looked at Halley’s Comet as a setting for their tales. Perhaps the one that is most scientifically accurate is by hard science fiction authors, Gregory Benford and David Brin, who wrote in The Heart of the Comet, about a mission to Halley’s Comet. Arthur C. Clarke in his novel, 2061: Odyssey Three, also describes a manned mission to the famous comet. Sir Frederick Hoyle, one of the pioneers of the panspermia concept, wrote the simply titled, Comet Halley, about life being discovered there.

In our lifetime humans have been witness to the destructive power of a comet. Fortunately, it was the planet Jupiter that pulled the comet from any possible course that could have resulted in an earthly impact. It has been now speculated that for intelligent life to evolve in a solar system, there needs to be a “cosmic vacuum cleaner” such as a Jupiter to clean up cosmic debris such as comets before they can destroy life that is evolving elsewhere in the system.

In July 1994, the Comet Shoemaker-Levy 9 hit Jupiter. It was almost as if some supreme intelligence had wanted the human race to see the event just to make us understand how lucky we are to have our island in the sky, the planet Earth. Not only was the event seen by earthbound telescopes, but by the Hubble Space Telescope, and if that were not enough, by the Galileo spacecraft which was situated to almost have a front-row seat to the event.

Another delivery mechanism for spores and organics from space come in the form of meteoroids. Meteoroids are rocky or metallic objects travelling through space. As the meteoroid hits the Earth’s atmosphere, it can appear as a meteor or “shooting star” as friction with the Earth’s atmosphere heats the object up to incandescence. When the object hits the ground it is known as a meteorite. They can range anywhere from dust to pebbles to small rocks and even large bodies such as the asteroid strike that killed off the dinosaurs about 65 million years ago. It has been estimated that up to fifteen thousand tonnes of debris falls to the Earth every year from space.

The source of meteoroids can be made up of ejecta from impacts on nearby objects in our sky such as the Moon and Mars. In 1996, NASA introduced a meteorite, essentially ejecta from Mars that has a possible remnant of biological activity. Initially the news made headlines around the world, but conservatism in science won the day and public interest dwindled when scientists began to offer alternate explanations for the structures. However, science does not stand still and in 2009, scientists from the Johnson Space Center reasserted the possibility that the meteorite showed evidence of past life as the structure of the magnetite particles found in the object are similar to those produced by Earth bacteria. Scientists extrapolated that if that was the case, Martian bacteria perhaps would produce similar particles. Unfortunately, recent work has demonstrated that these same magnetite particles could conceivably have been produced by shock waves as one might find during the collision between a meteorite and a planetary surface.

Other possible extraterrestrial sources of life on Earth can be an asteroid. Asteroids can come from several regions of space. One of the most likely is the asteroid belt that lies in between Mars and Jupiter.

There are literally millions of asteroids and there are estimated to be between 1.1 and 1.9 million asteroids over one kilometer in diameter, many which are shattered remains of objects that failed to coalesce into larger planets. Most of them have a very stable orbit with relatively low eccentricity. However, due to strikes by other objects in the asteroid belt or perturbations of the effects of gravity, they may stray from their paths to potentially become a threat to life on Earth. The first asteroid that was discovered was Ceres in 1801 by Guiseppe Piazzi. It also happens to be the largest of the asteroids with a diameter of 945 kilometers, After that, more and more were being discovered. The name “asteroid,” meaning “star planet,” was first coined by Sir William Herschel the discoverer of Uranus.

Ceres has provided the most inspiration to writers. The first was written by Garrett Serviss who wrote Edison’s Conquest of Mars in 1898 about Martians engaged in a war with giants from Ceres. Jerry Pournelle’s Exiles to Glory describes a Ceres that serves as the setting for an interplanetary mystery. In Venus Belt by L. Neil Smith, Ceres is a world that is strewn with a network of highways that link smaller settlements to a large underground city. In The Stone Dogs, by S. M. Stirling, Ceres is home to the Alliance for Democracy.

In spite of the evidence of organic molecules in space, on comets and even meteorites, along with possible delivery mechanisms, there are some critics of panspermia. However, there is indirect evidence that it could be possible. For example, scientists are discovering increasingly older rocks on Earth which contain the stuff of life. In Greenland, the clock has been turned back 3.9 billion years. Therefore, the gap between the early Earth formation and the beginning of life is very narrow, making the possibility of seeding from outer space more attractive.

More evidence is suggested that the early Earth atmosphere may not have been as conducive to life as was originally thought. The Urey/Miller Experiment, conducted by Dr. Harold Urey and Dr. Stanley Miller in 1953, recreated what was believed to be an early Earth atmosphere and exposed the mixture to an electric charge to mimic lightning. The resultant soup contained amino acids, the building blocks of life but something was wrong.

Amino acids have a handedness much like you and me. In Earthly life-forming amino acids, the handedness of the molecules is left, whereas in Urey/Miller experiments the handedness of the resultant molecules was both in equal amounts. Extraterrestrial amino acids, on the other hand, which have been detected in interstellar clouds and in meteorites show a “left” dominance as well.

Recent analysis of comets by spacecraft show that they are riddled with organics. Even recent ground based observations show that this organic debris can be detected in the tails as well, meaning that a catastrophic impact with a comet is not necessary to seed another planet. When a comet passes through the inner solar system, part of it begins to boil away as a gas with dust forming the tail. Some of this dust is swept up by Earth’s gravity. NASA scientists have been able to snag some of this cometary dust with the ER2 aircraft that flies at twice the height of commercial jets. Analysis of the dust indicates that over fifty percent of it is organic.

Since the Earth is predominately covered by oceans, one would expect to find a number of extraterrestrial particles in the ocean. One study seems to verify this. In coastal seawater, there are over ten million particles of extraterrestrial dust per quart.

Comets can also release material to a planet or moon in the form of meteorites. Every August, the Earth passes through the orbit of Comet Swift-Tuttle, displaying one of amateur astronomy’s annual highlights, the Perseid meteor shower.

Certainly the possibility of meteorites being a source of alien organic chemistry or even microbes is not lost to science fiction. In an interesting tale by Paul Preuss, Small Bodies, a fundamentalist preacher and a scientist discover fossils on an asteroid. Interestingly enough, though Preuss’ tale is fiction, there may be an actual scientific analogue. A meteorite that may hold some promise of life from outside the Earth, but also a lot of disagreement in the scientific community, is the Polonnaruwa meteroite that fell in December 29, 2012 in Sri Lanka. Chandra Wickramasinghe published that his team had found fossilized diatoms inside the meteorite. One problem is that peers did not recognize the rock as a meteorite and therefore are not recording nor analyzing it.

It is, therefore, very possible that the Earth was seeded by organics and perhaps even bacteria from the comets, asteroids and even meteorites of the past. However, what would happen with the energy of impact? Calculations show that the heat generated by impact or explosion actually still allows the organics to arrive intact on Earth.

The evidence is mounting. Perhaps life on our planet is not native at all. It may mean that we are truly alien and that our early space-faring predecessors were blessed with finding this rich and varied planet for the taking. The more evidence that there is for panspermia also bodes well for life elsewhere not only in our Solar System but in the rest of the universe as well. Life may indeed have been created in the empty reaches of space and colonized the planets through transmission of materials by comets. Hoyle has been vindicated and the theory that was blasted by Asimov as being unworthy of consideration is gaining a following.

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