Image credit: NASA/JPL-Caltech
Regarding higher carbon based life forms, our planetary neighbor Mars may be a rare exception. Mysterious structures are in many locations on Mars, not just in Cydonia, and include immense translucent tubular structures, partly under ground. Patches of green resembling plant growth appear and disappear with the seasons; there is increasing evidence for liquid water on the surface, and increasing evidence that the Martian atmosphere, while very thin, is denser than we have been told. And the Mars Orbiter has photographed large structures that look like trees.
Fairly complex organic compounds have been detected in space in the interstellar gas clouds. These include amino acids like glycine, in both left handed and right handed forms; the amino acids here on Earth are all left handed, or laevorotatory. Drinkers will be happy to hear that ethanol (C2H5OH) is also in the clouds, and glycoaldehyde (C2H4O2), which can combine with other compounds to form ribose and glucose; ribose is one of the building blocks of nucleic acids. Carbonaceous chondrites, a form of meteor, contain minerals like serpentine and olivine, also found on Earth, but they also contain some amino acids and polycyclic aromatic hydrocarbons.
Here on Earth, there are bacteria called extremophiles due to their ability to withstand extreme conditions. Most of these are chemosynthetic prokaryotes, meaning that they can survive without photosynthesis and without consuming other organisms or organic materials. Prokaryotes have no nucleus, nucleolus, or nuclear membrane; their DNA is spread throughout the cell. Biologists currently believe that there are at least five kingdoms of living organisms: monera (prokaryotes) protist (eukaryotes, with a nucleus and nuclear membrane) , plants, funghi, and animals. Some believe that some extremophiles are so radically different from everything else that they should be placed in a sixth kingdom: archaea. Extremophiles include acidophiles that can survive in a pH of three or less, endoliths living in pores in rocks at least as deep as two miles down in Earth's crust, hyperthermophiles living at temperatures of 80-122 degrees centigrage, and psychotrophs that live in sub freezing cold. The endoliths derive energy from chemical reactions involving iron, potassium, and sulfur. Some extremophiles get energy from hydrogen in hot springs. Extremophiles survive in anoxic ocean basins and seafloor hydrothermal vents. Polyextremophiles survive combinations of extreme conditions. Some, like deinococcus radiodurans can stand a 15,000 gray dose of gamma radiation; a dose of ten will kill a human being. These organisms could probably survive in space itself.
It is beginning to appear that life can flourish anywhere there is liquid water and the temperatures are not too extreme. We are accustomed here on Earth to life that ultimately depends on the Sun for energy, but planets and moons also produce energy internally; this is what drives vulcanism on Earth. Jupiter's moon Europa is white in color with few meteor craters, and there are systems of large cracks on the surface that change over time. It is virtually certain that, beneath a crust of ice, there is an ocean of liquid water kept warm by the moon's internal heat, which is generated by tidal stresses as it orbits Jupiter. Many astronomers believe that similar conditions may exist deep within another Jovian moon, Callisto. There is also likely to be considerable heat being generated within Ganymede (another moon of Jupiter), Saturn's moon Titan, and perhaps other moons in the outer Solar System. In fact, there is a possibility that extremophile bacteria are common throughout the universe, including within large, planetary sized objects between the stars.
But what of higher, perhaps even intelligent life forms? At the risk of being overly speculative, we can consider the possibility of a non-carbon life forms. People used to speculate about life based on silicon, which can be made to form compounds with long chain like molecules, just as carbon does. But it does not do this naturally, and silicon compounds cannot have the right and left handed forms believed to be necessary for enzymes in cells to function. And, if silicon life exists, why have we not found it here on Earth?
But there is another possibility. The idea that at least some ufos are paranormal manifestations or even bizarre life forms dwelling in our atmosphere and perhaps beyond it, is very old.
John Keel and Jacques Vallee have long speculated about the paranormal aspects of many ufos, and people like Ivan T. Sanderson and Trevor James Constable have suggested that ufos might themselves be living organisms. We should not draw too sharp a line between paranormal and alive. Paul Devereux and Paul Muir have studied orbs and earth lights near sacred sites, and then there are recurrent lights seen flying around in places like Marfa, Texas, Brown Mountain ridge in North Carolina, Toppenish Ridge in Washington, and the Hessdalen Valley in Norway. Researcher Jose Escamilla and others have videotaped "rods," which look like bizarre creatures flying at high speed. Shuttle pilot (now retired) Story Musgrave has described and videotaped a serpentine blob in space that has defied conventional explanation, and the objects filmed in space between the Earth and the Moon by astronauts on several Apollo missions could as easily be a life form as a craft.
If these things are in some sense alive, and seemingly exist even in space above our atmosphere, they could very well be common throughout the universe, and perhaps at least some of them are intelligent. We can only speculate as to their composition and structure; Biologist Rupert Sheldrake has suggested that our familiar life forms may owe their structure and development to "morphogenetic fields" which form a kind of paranormal template. Could such fields exist in our atmosphere and even beyond, giving structure to various substances like air, water, or the thin wisps of gas in the near vaccum of space?
If so, the universe may be teeming with such creatures, an idea suggested by the late British author C.S. Lewis.
William B Stoecker