The notion that life somehow originated on another planet and then came to Earth via outer space holds a wistful obsession for many evolutionists. This is because:
They have been unable to explain the origin of life on Earth, and even the ”simplest” living cell is now known to be unimaginably complex.
As life has been found deeper and deeper in the fossil record,1 and so in older and older strata according to evolutionary dogma, many are now saying that there has not been enough time for life to have evolved on Earth; thus an older planet is needed.
Of course, postulating that life began on another planet does not solve the evolutionists’ problem of just how non-living chemicals could have turned into a living cell — it merely transfers it to another place.
Conditions for life
The optimum place for life as we know it on Earth2 to exist elsewhere in space would be a planet with features just like those of Earth. These include having a star very like our own sun (an exceptionally stable star),3 being the right distance from its sun,4 as well as having an orbit5 and speed of rotation6 that would maintain a suitable temperature range, and hence fulfil the “Goldilocks criterion”—not too hot, not too cold, just right. Another essential would be the presence of liquid water—in living cells, water provides a liquid medium, necessary for amino acids and other organic molecules to mingle and react.7
Also needed would be an atmosphere that was non-poisonous,8 and which would also absorb or deflect lethal doses of ultraviolet light, x-rays, and gamma rays, as well as a magnetic field strong enough to deflect the solar wind (a stream of high-energy charged particles).9 Complex life forms would need oxygen to be present in the right proportion. Earth is just right for life.10
In the past, some researchers believed that Mars once fulfilled enough of these conditions for life to have existed there; however, many scientists no longer accept this. In particular, most now reject the claim that a small “Mars meteorite”, picked up in Antarctica in 1984, contained fossilised micro-organisms.11,12 And there are increasing doubts that Mars was ever as warm and as wet as thought, despite the claims of catastrophic flooding.
The latest setback for the evolutionist “true believers” is that analysis of meteorites believed to have originated from Mars has shown that the sulfur isotopes they contain were produced by atmospheric chemical reactions, not by bacteria.13 Further disappointment has been the failure of NASA’s latest two Mars missions and the loss of the Mars landing crafts.
There is, in fact, no evidence that life originated on Mars. Or for that matter on Europa, one of Jupiter’s moons, which may hold some liquid water, but has few, if any, of the other conditions necessary for life.
Astrobiology (or exobiology—the study of/search for extraterrestrial life) has been given a shot in the arm recently now that researchers have developed two techniques for looking for extrasolar planets, i.e. those which may orbit stars beyond our solar system.
Planets do not shine by their own light, but reflect the light they receive from the star they orbit. As this reflected light could be as feeble as one billionth of that of the host star, an indirect technique for “seeing” such planets has been devised.
As a planet revolves around its star, it and the star tug on each other with an equal and opposite gravitational force. The pull of the planet on the much more massive star causes the star to move slightly towards the planet, as the planet swings around it. This may be seen from Earth as a periodic (i.e. regularly recurring) “wobble” on the part of that star.15,16
Another technique is that, when a planet passes in front of its star, it could, slightly but periodically, dim its star’s yellow-white glow. To detect this, an observer on Earth would need to be in exactly the same plane as the planet’s orbit.
What has been found?
Using special hardware and software to detect this wobble, and applying the “wobble-means-planet” theory, researchers have claimed to have found some 573 extrasolar planets (as of 9 August 2011—Ed.), including the first claimed three-planet solar system (around Upsilon Andromedae, about 44 light years from Earth).17
None of the claimed extrasolar planets fulfil any of the conditions needed to support life, so the search continues for Earth-sized planets (the optimum size for life as we know it). An Earth-sized planet would have about 1/300th of the gravitational pull of Jupiter (at the same distance), as Jupiter is 318 times the mass of Earth, and so any wobble an Earth-sized planet might cause would be too small to be detected with current equipment. Further research is proceeding.
If any extrasolar planets capable of supporting life were to be found, several major problems would inhibit any rocks from carrying such life to Earth. These are:
1. The need to achieve escape velocity
For a rock (or spacecraft) to break free from the pull of gravity of its mother planet, it must achieve a speed called the escape velocity. For Earth this is 11.18 km per second, or 40,248 kph (25,009 mph). For Mars it is 5.02 km per second, or 18,072 kph (11,229 mph). As volcanoes do not eject materials at these speeds, scientists postulate that rocks are blasted from planets and into space through giant asteroid collisions.
2. The tyranny of distance
The nearest star to Earth is Alpha Centauri. It is 4.37 light years away, which means that light—travelling at 300,000 km (186,000 miles) per second—takes 4.37 years to reach us, 40 million million km away. If an Earth-sized planet (the optimum size) were orbiting Alpha Centauri and a rock were blasted from it at the speed of Earth’s escape velocity, the object would take 115,000 years to get here.18
Any rock coming from an Earth-sized planet at the comparatively close distance of 40 light years away (or 1/2500th of the diameter of the Milky Way) would take over a million years to get here.
3. Other problems
“Radiation would destroy DNA on a journey between stars,” says Francis Cucincotta of the NASA Johnson Space Centre in Houston.19 Other hazards would be: the near-absolute-zero temperature of space, without a space suit; the lack of nutrients and/or oxygen in the vacuum of space, without a space vehicle; entry into Earth’s atmosphere, without a heat shield, which has been proven to burn up bacteria20; and impact with planet Earth, without a parachute.
Some idea of the force of such an impact was demonstrated by the catastrophic collision of 20 fragments of Comet Shoemaker-Levy 9 with Jupiter on July 16–22, 1994 (see images to the right).
All in all, interstellar space travel for living organisms is sheer wishful thinking.
There are no biblical or moral reasons why God should not have formed other planets, when He formed those in our own solar system, on Day 4 of Creation Week (Genesis 1:14–19).
Whether there is life on any planet other than Earth is another matter. The Bible teaches that life began on Earth through a process of commanded-by-God creation (Genesis 1:11–27). It also tells us that God’s purposes are centred on Earth. Thus God created Earth (on Day 1) before He created “the lights in the firmament of heaven” (on Day 4), which were “to divide the day from the night” and were “for signs, and for seasons, and for days, and years” (Genesis 1:14), i.e. for the benefit of mankind.
Man and woman were both “made in the likeness of God” (Genesis 1:27). This, coupled with factors such as the Fall, the Incarnation, the redemption of mankind through the once-only death and Resurrection of the Lord Jesus Christ, the Second Coming of Christ to Earth, and the coming Judgment of all mankind, show Earth’s unique importance among the billions of billions of stars in the universe. This is despite the frequent belittling, by evolutionists, of the importance of Earth.
The above also implies that God did not create any other life forms elsewhere in the universe.21
If, however, some form of microbial life should one day be found on Mars, Europa, or elsewhere within our solar system, this would not prove that it had evolved (or been created) there. Such life could be seeded from Earth, because:
If rocks can be blasted from Mars to Earth, the process should also be possible from Earth to Mars, as physicist Paul Davies suggests.22
Bacterial spores may be able to survive the relatively short journey involved compared to interstellar travel.
Spores in Earth’s upper atmosphere could be pushed into space and then to another planet or moon by the solar wind.
There is always the risk of contamination by Earth bacteria of the surface of a planet or moon on which any man-made space vehicle lands and digs.
Such a find could be used to reinforce the idea that it is easy, if not inevitable, for life to arise by itself from lifeless chemicals.
If it can be shown that life exists elsewhere in space, it would assist those who claim that Earth life began “out there” (see main text).
Projects to investigate life elsewhere in the universe overshadow more mundane Earth-directed research in attracting public interest and tax dollars!
Space-life enthusiasts like to say that “absence of evidence is not evidence of absence”. Perhaps, but they have never been able to answer the famous question posed by Nobel-Prize-winning physicist Enrico Fermi half a century ago concerning all the other alleged civilizations in the universe: “Well then, where is everybody?” SETI, the Search for Extraterrestrial Intelligence, which now uses equipment that scans 28 million radio frequencies per second, has failed to obtain a single “intelligent” signal from outer space in over 50 years.
In April 2000, 600 astronomers, biologists, chemists, geologists, and other researchers met at the First Astrobiology Science Conference, held at NASA’s Ames Research Centre, California,23 to evaluate the evidence on whether, biologically speaking, we are alone in the universe. The predominant mood of pessimism was encapsulated by British palenontologist Simon Conway Morris’s comment: “I don’t think there is anything out there at all except ourselves,” and Dan Cleese, a Mars program scientist at NASA’s Pasadena Jet Propulsion Laboratory, who said that it is time to “tone down expectations”.24
The fervent search to authenticate “astrobiology” has generated much data, but to date this has, if anything, strengthened the Genesis record of the creation of life on Earth. Contrary to the claims of evolutionists and the many imaginative Hollywood epics like ET, Star Wars, Independence Day, etc., the coming of aliens to Earth from outer space will always remain in the realm of science fiction.
Editorial note: As this article originally appeared in 2000, the section “Search for other planets” has been updated and relevant articles post-2000 have been included in the references. Also the box “Alien Visitors to Earth?” (below) has kindly been supplied by Dr Jonathan Sarfati.
Films involving intelligent life on other planets have been some of the best box-office smashes, e.g. Avatar, the Star Wars and Star Trek films, Independence Day. All these are cultural icons. But as we have pointed out many times, intelligent life on other planets is contradicted by Scripture,25 and presupposes chemical evolution: that life evolved from non-living chemicals.26 And as will be shown, there are huge scientific problems for the idea of interstellar space travel as well, including a huge lack of energy.
Distances between stars are literally astronomical. The closest star system to ours is Alpha Centauri, 4.37 light years away. I.e. its light, although travelling at 300,000 km/s (186,000 mps), takes 4.37 years to get here. One light year is just under 10 trillion km (about 6 trillion miles). Furthermore, Einstein’s theory of Special Relativity teaches that any mass increases as it approaches the speed of light, thus requiring even more energy to accelerate it. But the problems for hypothetical aliens start well before this becomes an issue.27
Perhaps, it would be good to update the inset box about impacts using momentum instead of energy equations, especially the part about hitting a snowflake at high velocity. As a mechanical engineer, in dynamics courses, we use impulse momentum to analyze collisions rather than energy equations. Energy is certainly the right analysis for interstellar travel, but the bit about collisions should be done using m1v1 + fdt = m2v2. To accelerate a 0.1 mg snow flake up to 0.1*c in (generously) 1 ms, from rest would require a force of f = 3 x 107 N which would convert to the weight of about 300 elephants to give it meaning to non-technical folks.