Despite the geological appearance of Earth, it has been hit many times by asteroids. Most of these impacts occurred while the Earth was still forming. A major asteroid impact about 65 million years ago is said to have killed off the dinosaurs and most of the other life-forms living in that period. This impact was in the Yucatan Peninsula, about 200 miles west of Cancun. The asteroid was about 10 km in size, with the energy equivalent of more than 100 million megatons or 5 billion Hiroshima atomic bombs. The results are supposedly the end of the dinosaurs due to the cloud of dust that blocked the sun, the sudden drop in temperature, tsunamis, and other extreme changes in the environment.
The same thing might happen once again if a similarly sized asteroid or comet should come in contact with the Earth. This picture shows the paths of the tsunamis that would follow a water impact (noted by the star).
The possibility of this happening is not overly slim. A more recent impact is the once in Tunguska, Siberia on June 30, 1908. While the asteroid only grazed the atmosphere, it exploded in the air about 5 kilometers (3 miles, or 15, 000 feet) above remote Tunguska. However, the energy released was equivalent to a nuclear bomb.
In fact, the explosion was greater than the Hiroshima or Nagasaki nuclear bombs. About 30 kilometers of forests fell flat, some bursting into flames. The shock wave caused much destruction within the city, throwing carpenters off buildings and breaking out windows. This picture shows the orbits of asteroids we know of, the yellow lines being ones that are most likely to hit Earth. Not good odds in my opinion. The evidence of all the impacts upon the Earth is very well hidden.
... are sometimes jarred from their positions from the impact of other asteroids. Although asteroids could destroy Earth if they come in contact with it ... 's population. This size of an asteroid would be the equivalent explosion to 2 million Hiroshima bombs. This explosion would cause destruction ...
Weather and time have worn down the vast majority of the craters created by impacts. Using seismic waves scientists have discovered the locations of many craters. This method helped find the crater from the Yucatan impact. Using computers they have been able to find out the effects of an impact, including how the ground would cave back in, forming the inner ring in some craters. They can also calculate the devastation that will occur, which is not always comforting data.
The Earth is constantly being passed by asteroids and we don’t even know it. There have been many near-earth objects (NEOs) that have come even closer to Earth than the moon. Detection is difficult, due to the size of the sky and our limited monitoring capabilities. Now there are new sensitive cameras that use sensors and computers to find the objects. Due to the very limited budget and the size of what has to be monitored, detection is still very difficult. With the current monitoring techniques, the chances of us knowing about an impact before it happens are slim.
We might not notice the NEO until it’s just about ready to send us all packing to the next life. Not much can be done to guarantee the stopping of an impact. What can be done is we can send a nuke up and blow it apart, hopefully into pieces small enough to burn in the atmosphere. Also using nukes we can try and nudge the asteroid so that its path only grazes the Earth’s atmosphere, and misses making an impact. Until the detection program is given better funding, options are limited and even seen as impossible. While some say it’s mere science fiction to think that we could be impacted, the event could happen sooner than you think..