Asteroids and Comets
At the time when the proof that such an occurrence had already taken place on Earth was first discovered in the early 1980’s, there was a threat of a similar crash. The American physicist Luis Alvarez and his son William proposed the hypothesis that about 65 million years ago (at the end of the Cretaceous period), as a result of a meteorite hitting the Earth, the climates had changed altogether and that this had led to the extinction of many land and marine species. According to this theory, which is supported by fossils found throughout the world, approximately 65 million years ago, when a meteorite almost 10 kilometers in diameter hit the Earth, a cloud of dust formed, leaving the Earth in darkness for years; the result of this was that rays of the Sun could not reach the Earth, thereby preventing photosynthesis, and consequently the possibility of plant life. This in turn led to a chain reaction, eventually leading to the extinction of some animal species (including dinosaurs) that fed on plants and other animals. The cooling of the air, the poisonous gases that filled up the atmosphere as a result of forest fires, and the rising of the acidity of the subsequent rain might all have played their roles in the extinction of land and marine animals. It seems that 8 out of 10 species disappeared from the face of the Earth in a few thousand years, or even less. The traces of the meteorite crash can also be seen in the iridium levels found in sediments from the Cretaceous-Tertiary boundary (This metal from the platinum group is found in small amounts on Earth, whereas in meteorites it is in abundance). In the quartz crystals that had undergone shock it was visible that they had been subjected to high pressure due to a crash; the nickel minerals showed that a nickel-rich meteorite had been oxidized in the atmosphere. The location of the meteorite crash was found in 1991. On the shores of the Mexican peninsula of Yucatan, under a one kilometer stratum of sedimentation, a crash crater with a diameter of 260 kilometers was discovered through gravimetric methods. Its age was found to be 65 million years. Another factor that could have led to great amounts of carbonic gas and sulfur oxide being introduced into the atmosphere would have been intense volcanic activity, which it is understood took place at the end of the Cretaceous period; this too could have contributed to the degeneration of the climate.
This was not a one-off incident. Approximately 445 million years ago (at the end of the Ordovician period) gamma rays from space could easily have been the cause of a mass extinction of two-thirds of all species on Earth. Gamma-ray explosions are the strongest explosions known. When huge stars implode into black holes at the end of their lives, they emanate very strong gamma rays as pulses at a particular frequency from their poles. If such an explosion should happen in our galaxy and should the rays head toward us, it would be very destructive indeed. It has been understood that species like “trilobites,” which continued to live very close to the ocean surface suffered great losses during this period. This could be explained only by the occurrence of a gamma ray explosion, which would affect the creatures on land and the ocean surface, but would not greatly trouble the deep-water creatures (Hecht, 2003).
Around 250 million years ago (the Permian-Triassic boundary), as a result of another mass extinction, probably 90% of marine species and 705 land species disappeared from the face of the Earth. These extinctions were attributed to the rapid changes in the climate and sudden changes in sea-levels or intense volcanic activity. To these factors was added the “cosmic cause.” In the rock sediment specimens of this period, the isotope distribution of helium and argon gases was more similar to the distribution in meteorites than to that of the rocks on Earth. In 2001 American geochemists and Australian geologists found new evidence concerning the meteorite crash.
In the 1990’s, astrophysicists understood that the balance in the solar system was very sensitive, and that it was impossible to predict the long term orbit of a heavenly body. Apart from the regular movements of planets and their satellites, innumerable comets and asteroids, at various angles to the system, are engaged in rotating motions which are impossible to pre-calculate. In 1996, the Shoemaker-Levy star fell onto Jupiter bit by bit, tearing away balls of fire as big as the Earth. So, what sort of objects can hit the Earth?
Andromeda, the closest galaxy to ours, is coming toward us at a speed of 400,000 kilometers per hour. But because it is two million light years away it is set to collide with our galaxy only five billion years later (if Doomsday does not arrive before then!) According to the information we have today, since the neighboring stars change their positions along with the Sun within the great circular movement of the Milky Way, the possibility of crashing into one of these is nearly non-existent. The planets in the solar system give us no reason for concern either. Their orbits, in which they have been excellently placed, do not intersect with that of the Earth. The Moon does not present a threat either. It is also not anticipated that any machine parts from satellites will reach an acceleration that could be disastrous as they enter the atmosphere. What threats remain are asteroids and comets that have a tendency to hit the Earth.
Asteroids are large objects that have a rock-like structure, yet are not big enough to be considered planets. Their diameters range from a couple of meters to 30 kilometers. Many asteroids that are close to us move in orbits that intersect those of the Earth. Asteroid 3753 (1986 TO), which has an orbit that has a dynamic relationship to ours, seems to be another satellite to the Earth, along with the Moon. (Wiegert et al., 1997). Comets, on the other hand, are balls of dust that have heated up as they pass close to the Sun and are adorned with bright tails. The possibility of a crash stems from these two groups. These comets revolve around the Sun in specific orbits, and it is without a doubt that they have a great significance for the system; these objects are concentrated in three major areas. The first area is a large belt between Mars and Jupiter (The Asteroid Belt). Here there are approximately a million asteroids of diameters greater than a kilometer. Further away, beyond Neptune, in the Kuiper belt, whose size is 30-100 times greater than the distance between the Earth and the Sun, it is believed that there are more than a trillion comets. Another source of meteorites is the border area of the solar system, which opens up to wider space, the sphere shaped Oort Cloud, whose diameter is 40 thousand times greater than the distance between the Earth and the Sun. (Poirier & Greffoz, 2001)
When we consider an asteroid of a kilometer in diameter and which is further away than Mars, it hardly seems bigger than a grain of sand 100 kilometers away from Earth. In 1998, NASA started a project which aims to use telescopes to identify (within 10 years) 90% of the asteroids of more than a kilometer in diameter which are moving toward Earth.
Unity in Abundance
The solar orbits of those distant bodies that cannot be identified can be disturbed by even the slightest intervention. It is enough that the orbit of an asteroid should be ever so slightly disturbed as it passes near one of the satellites of Jupiter for it to leave its orbit and start heading toward us. Our existence is bound to such vast Compassion, manifesting itself in such a fine equilibrium; this only goes to demonstrate to us that it is only He Who protects us to Whom we should be grateful, not only for our Creation, but also for every step of our life and every breath; it is He Who is Alive and Who is the Source. On the other hand, our condition of being human and our responsibility to look after what has been given into our keeping spurs us to search for apparent causes in this world. Since we do not know when or why our deaths will come upon us, we take precautions against situations that may be dangerous and try to stay alive; in the same way, as we do not know when Doomsday will come nor what its apparent cause will be, we must take precautions against risks like meteorites (without forgetting that the real affect and the final will lies always with God) in order to protect life on Earth. But we do not know what the scientists (and authorities with executive powers) who have the means to monitor the Universe with well-developed equipment feel; and with what feelings they inquire into the nature of these meteorites. We wonder if they are aware of the fact that the meteorites are in the Command of the One and Only, as are the Sun and the Earth and, indeed, the whole Universe. Can they acknowledge this fact openly, without feeling the psychological terror that the science of the “denying school” imposes? Can they see the falsity of using the word “threat” for meteorites?
What Sort of Measures for What Sort of Life?
Asteroids can reach a speed of 100,000 kph, while comets can get up to 150,000 kph. Even if the mass may be small, at such speeds a great amount of energy is produced. According to Brian Toon of Colorado University, if a meteorite crashes on to the Earth, the surface of the Earth will catch fire and the sky will be filled with very hot particles that are lifted from the ground (Hecht, 2002). The amount of damage that the crash will cause to humanity is dependent on whether the meteorite crashes into the middle of the ocean or into a city. According to researchers, if the diameter of the meteorite is less than 300 meters, then the people living in the probable crash site should be evacuated. If the meteorite is quite large, then one should send a rocket with a nuclear head toward it in order to blow it up and try to diverge it from its orbit. But this intervention could be risky; the energy of the rocket could be less than needed, and the radioactive shower could fall back down to Earth. Other options, like using rockets without nuclear heads or other asteroids, exploding the meteorite with lasers or trying to decrease its size through piercing it with drills could be attempted. But all these are technologically impossible today. It is not even known whether the time between the determination of the body"s approach toward the Earth and its probable crash time will be enough for us to determine what to do. In the worst case scenario, a great crash and massive deaths could be the result. The probable destructive force of these objects can be inferred from nuclear tests that have been carried out. But the determination and analysis of occurrences in the past has proven to be difficult. Since three-quarters of the world has been covered with water for billions of years, the traces of crashes under the seas and the oceans do not remain, and the crash sites on land are eroded away, sometimes even as quickly as in a couple thousand years.
So is there nothing else that can fall upon our heads? For instance, anti-matter. Anti-matter is composed of antiparticles, which are just like ordinary protons, electrons, and neutrons except they have opposite electrical charges and magnetic moments. When antimatter and matter collide, both are annihilated. The existence of anti-matter in the universe has been demonstrated by particle accelerators. The entry of anti-matter the size of a pebble into the atmosphere could be enough for matter and anti-matter to disappear in a great whirl of energy, greater than the one caused by the Hiroshima bomb. We cannot even imagine what would happen if an anti-meteorite with a diameter of a kilometer should hit the Earth. Nevertheless, the French astrophysicist Marc LachiÃ¨ze-Rey said: “Had there been an anti-matter asteroid in our galaxy, it would emanate x-rays when it disappeared with the material it had around it.”
Now let us get back to usual asteroids. There was the greatest crash of the 20th century, which took place in June 1908 in Tunguska (Russia). It is believed that there a small asteroid cleared 2,000 km2 of Siberian forest. A similar incident was the strange explosion that lit up the Jordanian sky, shattering the rocks in the area on 18 April 2001. It is believed that the 100 km2 diameter of the Popigay crater in Siberia was caused by a meteorite (Bottomley et al., 1997). In the last eight years US satellites that look for nuclear explosions have determined nearly 300 optic blazes were caused by small meteorites (diameters of 50-100 meters).
According to Bill Napier from the Armagh Observatory in Northern Ireland, comets present a greater danger. Comets with tails composed of gas and dust and with structures of ice are much rarer than those with a rock-like structure, and they may damage the Earth in different ways. A comet that evaporates under the rays of the Sun would leave billions of particles of dust in the orbit of the Earth. If the dust were to shower down onto the Earth, it could block the rays of the Sun from reaching the Earth, thus triggering the start of a new ice age. There are still four known objects in space with diameters of more than a hundred kilometers that are believed to be comets. There may be 2,000 more in the Oort Cloud, beyond Pluto (Samuel, 2001) In short, there are many objects moving around our planet that could end our life, and yet, life on Earth has continued for billions of years.
He Makes Us Live and Die
On the other hand, after a crater caused by a meteorite cools down, life can regenerate. Devon Island in Canada is a polar desert on which there are no plants and animals. There, the Haughton crater, with a diameter of nearly 24 kilometres, is believed to have been caused by a meteorite crash that happened 23 million years ago. As far as we can gather from fossils and other traces, there were probably thick forests in this area; the forest was lost and the shock wave that took place here destroyed most of the other living things with an explosion and the subsequent heat. About a thousand years later, life came back to Haughton. The subterranean waters were heated as a result of the crash, thus presenting a perfect living environment of hydrothermal systems for organisms that live in colonies, such as bacteria and algae. This activity has been observed in 70 of 170 crash craters. It is not know when life was created, but the first traces go back nearly 3.8 billion years. That is to say, the Earth might have been full of these hydrothermal systems at the beginning of its creation. The craters on the Moon, on the other hand, show us that meteorite crashes in the past were 15 times more common (Osinski, 2003). Thus it is impossible to explain, through reason, how life could have been created in a period of our world when it was—apparently—extremely unfavorable for life.
There are other influences that reach the Earth from space. About a thousand years ago the Earth was going through its last ice-age. The Aquila star constellation, which can be observed from the Northern Hemisphere, probably went through an intense upheaval and emanated radiation in great amounts in all directions. This wave of high energy traveled through space for 20,000 years, hitting the Pacific Ocean on the evening of 27th August 1998. As far as it could be recorded with terrestrial and orbital observation, on that summer night the Earth was bombarded with gamma and X-rays for five minutes. The radiation scattered as it reached the lower strata of the atmosphere.
A greater energy could have reached the Earth from interstellar space and caused destruction of matter. It is believed that this incident that took place in 1998 was caused due to the tearing up of the surface of a “magnetar”; this is a sort of a neutron star. It is believed that that magnetar was of a diameter measuring 35 kilometer, but denser than the Sun; a thimble-size portion of it would have weighed as much as 100 million tons. This star revolved around itself like all neutron stars and as a result created a great magnetic field. If this magnetar had been only 10 thousand light years away then the energy that reached the Earth would have been four times greater; it may have been strong enough to damage the ozone layer (Ward & Brownlee, 2000).
At the start of the 19th century, Georges Cuvier, a French palaeontologist and a practicing Christian, stated that disasters played a determining role in the life story of the Earth, basing this view on what befell the people the Prophet Noah. In Darwin"s model there was no space for disasters. The speculation of “The course of evolution” became a dogmatic model which was taught under the name of scientific theory. Today, Cuvier"s concept of “disaster” is being accepted once again in the West. Life has, now and then, been faced with sudden disasters which have affected its natural course. For 200 million years, the dinosaurs were the sovereigns of the Earth; the mammals were few. But a stone fell out of the sky and suddenly the dynasty of the dinosaurs ended. Could the same thing not happen to the false dynasty of humanity? All these possibilities of termination should lead us (and the experts) to think more carefully about our existence, life, Earth and humanity as a whole. But, unfortunately, this is not what happens, and countries which worry about meteorites only in relation to themselves have destroyed certain regions in the world with bombs, creating the effect of meteorites long before the meteorites themselves reach us; such people see nothing wrong in causing the deaths of many people. The existence of meteorites (and other cosmic phenomena) carries many divine truths. We are not alone in the time-space dimension; all these planets and their satellites, innumerable comets and asteroids move around and among us and yet they do not effect the accurate and sensitive functioning of the system; in truth, they constitute a vital part of its accuracy. They have submitted to the great Will that has created them:
Do they not then look up to heaven above them how We have made it and adorned it and how it has no gaps?(Qaf 50:6)
The atmosphere and the magnetosphere that surround our Earth as a token of compassion and protection serves, under Divine orders, as the shield against solar explosions that regularly take place every 11 years, against harmful cosmic radiation and particles. Otherwise, conditions that are very unfavorable to life would have been the reality, with craters pitting the surface of the Earth, just as we see on the surface of the Moon, which has no atmospheric or magnetic shields.
On the other hand, the possibility of a meteorite colliding with the Earth makes us think of other things as well: How will the end of the Earth come about; through collision with a meteorite, or through more complex phenomena? This is something we cannot, and maybe do not, need to know for sure: what is more important is that the Earth will end, that the day that has been promised will come, that the day described in the Qur'an will make us shudder, and that we have to tread accordingly on this Earth. On this issue Said Nursi points to an important truth concerning faith: “If Earth were to explode, those servants of God with truly illuminated hearts would not be frightened—they might even consider it a marvel of the Eternally Besought"s Power. A rationalist but unbelieving philosopher might tremble at the sight of a comet, lest it should strike Earth. (This was how some Americans reacted to the recent sighting of Haley"s comet.)”
Another lesson for contemplation that the comets offers us could be the following: “The movements of heavenly bodies in the sky (the world"s roof), the appearance of comets and new stars while some others are extinguished, as well as solar and lunar eclipses, demonstrate that it is not stable and therefore is making its way toward a final ruin. However slow its changes are, they also show that the world is mortal and moves to its inevitable end.”
Our life has been given into our safe keeping by our Lord; and so we must try to protect it to the best of our ability. In that spirit, we can take precautions against a comet that comes toward our Earth in order to protect life; we may be able to smash it into pieces using the technology that we have. But if not today, tomorrow, or soon Doomsday will arrive; we should not forget that, just as we should not forget that rendering meteors ineffective is a gift from God Who is the true holder of knowledge and power. But will such a success lead humanity to assume a more ungrateful and arrogant position toward God, or will it end in our praising God and giving Him thanks, as did the Prophet Solomon? The last position is the following:
And call not God with any other god; there is no god but He, every thing is perishable but He; His is the judgment, and to Him you shall be brought back (Qasas 28:88).
Bottomley, R., Grieve, R., York, D. & Masaitis, V., The age of the Popigai impact event and its relation to events at the Eocene/Oligocene boundary, Nature, Vol 388, pp.365-368.
Hecht, J., The End of the World, New Scientist, 2 February 2002.
Hecht, J., Did a Gamma-Ray Burst Devastate Life on Earth? New Scientist, 27 September 2003.
Osinski, G., Shocked into Life, New Scientist, 13 September 2003.
Poirier, H. & Greffoz, V., Asterodes: La Menace se PrÃ©cise, Science & Vie, no 1006, Juillet, Paris.
Samuel, E., Sting in the Tail, New Scientist, 24 March 2001.
Ward, P.D. & Brownlee, D., Rare Earth, Copernicus Books, New York: 2000
Wiegert, P.A., Innane, K.A. & Mikkola, S., An Asteroidal Companion to the Earth, Nature, Vol. 387, pp. 685 - 686.
Nursi, S., The Words, the Third Word, the Twenty-Fifth Word, Kaynak, Izmir: 1997.