About 4.5 billion years ago, our solar system was beginning to form. As our Sun, its planets, and their moons were in the developmental stages, there was a lot of leftover debris and dust sized particles rampant in the general area.
The force of gravity of these celestial bodies in our early solar system began to have an effect on this debris, and as a result there were numerous impact collisions with the Sun, and on the surface of the planets, and their moons.
Probably every celestial body in our solar system has felt the effects of these impact collisions causing craters of varying size, but some display the devastation more than others. The reason being is that some of the planets and their moons have numerous types of erosion like wind, rain, volcanic eruptions, sand storms, etc. that cause the impact craters to dissolve over time.
However, if you look at our Moon even with a pair of any size binoculars, you will see an abundance of impact craters on its surface. The reason being is that the lunar craters are not subjected to almost any type of erosion except the solar wind.
Although the majority of debris in our solar system has dissipated due to numerous encounters with the Sun, our planets, and their moons due to gravitational attraction, there are still other sources of space artillery.
Between the orbit of Mars and Jupiter, there are thousands of very small planets called asteroids or planetoids. They range in size from small pebbles to the largest one named Ceres which is about 600 miles in diameter. It is believed that the asteroid belt is the remains of a planet that never formed or was blown apart by some catastrophic event.
There are some asteroids that were found to cross within the Earth’s orbit, and are called the Apollo asteroids. Most asteroids are irregular in shape similar to a potato. One asteroid named Hermes has passed within 478,500 miles from the Earth. Hermes was recently found to be two asteroids each about ¼ mile in diameter revolving around a common center of mass. Collisions within the asteroid belt are not uncommon. As a result, some of the debris heads in the direction of the Earth.
Another source of space artillery comes from comets. Basically a comet is a dirty snowball with a rock at its center along with ice and dust. This is called the nucleus of the comet. Many comets, the most famous being Halley’s Comet, travel around the Sun in egg shaped orbits. Each time the comet gets close to the Sun, the frozen gases and dust in the comet’s head vaporizes and forms the tail of the comet.
Over long periods of time, the frozen gases and dust from the comet diminishes, and all that is left is the rocky nucleus. It is thought that many of the Apollo asteroids are the dead nuclei of periodic comets.
When the nucleus of the comet has a close encounter with one of the planets in our solar system, they break up and leave debris scattered along the comet’s orbit. These remains are called meteoroids. When these meteoroids enter our atmosphere due to the Earth’s strong gravitation pull, they begin to heat up and glow as a result of friction. At this point they are called meteors or shooting stars as they appear like stars falling from the sky.
The majority of all meteors burn up in the Earth’s thick atmosphere. However, those that do reach the ground are called meteorites.
It is believed that a large meteorite or asteroid impacted the Earth about 65 million years ago producing an explosion equivalent to a 20,000 megaton hydrogen bomb. As a result, a thick cloud of dust and debris covered the Earth which the Sun was unable to penetrate for years. It is thought that this caused the extinction of the dinosaurs.
About 15 miles due west of Winslow, Arizona is the famous Barringer Meteor Crater. It is estimated that about 45,000 years ago, a large meteorite about the size of a two bedroom house struck the area causing widespread devastation probably killing all plant and animal life within a radius of about 50 miles..
The meteorite blew out nearly 400 million tons of rock and sand. It made a crater nearly ¾ miles across, and 650 feet deep. The rim of the crater rises nearly 120 feet above the surrounding area. This meteorite crater is open to the public for viewing.
It is estimated that the blast of this meteorite was equivalent to a 3 megaton hydrogen bomb. The main body of the meteorite probably weighed about 50,000 tons, but was never found. It was thought that the meteorite vaporized on impact.
On June30, 1908, a large meteorite or a group of them, hit near the town of Tunguska in eastern Siberia. Over six miles away from the point of impact, large trees were blown over. However,
no impact crater was found. People living about 30 miles away from the blast felt the shock in their homes.
Then on February 12, 1947, in the village of Novoprebka in eastern Siberia many meteorites hit the area. Numerous craters thirty to forty feet deep and as large as 75 feet in diameter were found. Some meteorites that were found weighed several hundred pounds.
The most recent meteorite encounter on the Earth occurred on February 15 of this year. At about 9:15 A.M. local time in Russia or 9:15 P.M. Central Standard Time in Kansas the night before, a very bright meteor was seen crossing the morning sky about 12 miles south of the town of Chelyabinsk. It exploded at an altitude of about 77,000 feet. It was estimated that it was about 60 feet in diameter, and was an Apollo asteroid. No one was killed by the shock wave of the explosion, but many were injured by fragments of flying window glass.
The chances of a large meteorite or asteroid hitting a very populated area on the surface of the Earth is very real, and will probably happen someday causing a major catastrophe. Two former movies entitled Armageddon and Asteroid cover an event such as this, and its consequences. These movies are worth watching.
To protect us from space artillery, astronomers are trying to track as many near Earth objects as possible to see if they pose any danger of collision with our planet. However, what can they do about it except to give us advanced warning of the oncoming collision.
On February 23, 2012, an asteroid about 150 feet in diameter was discovered by astronomers in Spain. It is called asteroid 2012 DA14. During its close approach this year, it passed only about 17,200 miles above the surface of the Earth. However, there are literally tens of thousands of asteroids less than 300 feet in diameter that are found to come fairly close to the Earth.
Between 1968 and 1972, man has flown to the Moon and back. However, since then we have only had manned spaceflights in low Earth orbit. If a large meteor or asteroid was found to be heading straight for the Earth, it would be advantageous to try to divert its course as far away from our planet as possible. Therefore, it has been suggested that we accelerate our manned space program to other planets and beyond to protect us from any future space artillery in addition to learning more about our solar system.