Some day earth will be hit by an asteroid, meteor or comet, Scientists of all class’s are looking to the sky’s for these objects 24 hours a day. Many pass by quite close all the time but their orbit keeps them away from hitting earth.
There is an asteroid called “Apophis” giving concern it will pass in 2013, 2029 and 2036. 2013 will be fine, but observations and tracking will take place and the governments will have to decide what to do in 2029, as 2036 could be the bad result.
The earths orbit is the outer white ring the asteroids orbit is the blue ring.
The asteroid’s risk has now been categorized as a 4 on the Torino Scale. The level 4 rating never before issued is reserved for “events meriting concern.
When it does pass close on April 13 2029, the Earth will deflect it and change its orbit. There’s a small possibility that if it passes through a particular point in space, the so-called keyhole, the Earth’s gravity will change things so that when it comes back around again in 2036, it will collide with us. The chance of Apophis passing through the keyhole, a 600-metre patch of space, is 1 in 5,500 based on current information.
If, at that stage, they cannot rule out an impact with Earth in 2036, the next chance to make better observations will not be until 2013.
Nasa has argued that a final decision on what to do about Apophis will have to be made at that stage.
An asteroid, meteor or a comet does not need to be large to devastate. One the size of a small garage would annihilate a large city like New York, London,Paris or Tokyo and would leave a 10km crater.
Still nowhere near the size of the biggest (there is a 300km crater on Earth), would have the destructive force of every one of the world’s 10,000 nuclear warheads combined.
It was 65 million years ago in what is now Yucatan the impact of a 10-kilometer wide asteroid it helped to bring about the K-T extinction, no animal bigger than a small chicken was able to survive. If man had lived on the planet at this time, he would have been destroyed by this event.
This event threw huge amounts of matter into the atmosphere in addition to this, it caused 2000 foot waves that may have all but completely emptied the Gulf of Mexico. This created months of darkness, much cooler temperatures globally, and the resulting harsh conditions which in turn led to the extinction of many species, including the last of the dinosaurs.
On the June 30th, 1908, at about 7:00 a.m. an explosion occurred in the skies over Tunguska, Siberia, located in Russia.
This explosion happened at anywhere between six-to-eight kilometers from ground zero, and the result was to lay waste to a vast region of pine forest of 2,150 square kilometers, felling more than 60 million trees.
The inhabitants seen a brilliant burst of light. the explosion was so loud and powerful enough to blow-out windows, temporarily blind and knock people to the ground. Had it happened fifty years later, scientists think it would most likely have spurred russia into a nuclear war.
Could we stop an Imminent Impact?
We would have been totally defenseless against one. But now with nuclear weapons, launching ICBM nuclear tipped rockets in an attempt to destroy it. But doing this could create a worse situation for ourselves. If it broke into pieces, the damage from multiple impacts could be just as bad as one big one.
The largest yet discovered is an awesome 25 kilometres in length. There are more than a million bigger than 50 metres across, each capable of destroying a city.
If a large one did hit, earthquakes would streak around the earth at thousands of kilometres an hour, destroying all in their path.
It would create a tidal wave between 1,000 and 2,000 feet high.
It would also trigger volcanic eruptions all over the world.
Gasses released into the atmosphere would cause acidic rain and destroy the ozone layer. A vast fireball would be sent into the sky.
The real danger would be from the dust clouds sent into the atmosphere. The amount of debris released into the upper atmosphere would block out the sun, trigger a nuclear winter and potentially kill all life on Earth.