The Arizona meteor crater is arguably the most famous meteor impact site on the planet and as a consequence of this, it is usually quite simply referred to as the ‘Meteor Crater’. Scientists deliberated over the possibilities for what had created this crater for many decades, before evidence from the Canyon Diablo Meteorite so overwhelmingly helped to prove that this was its definite true cause.
When viewing any photographs of this conspicuous scar to the planet’s crust, you may very well feel as though you are looking at a small section of another planet in our solar system. Perhaps Mercury would be a good example here. This desolate part of Arizona would have experienced an impact that has most recently been estimated as being equivalent to at least 150 Hiroshima atom bombs.
The meteorite would have been travelling to Earth at least at 11 km per second, just before it hit. The resulting impact resulted in the Arizona meteor crater which measures some 1.2 km across and up to 170 meters in depth.
This event is thought to have happened around 49,000 years ago, but timing estimates do still vary and range from anything between 20,000 and 50,000 years ago.
The most recent research, which has been undertaken by Drs. Jay Melosh and Gareth Collins from the University of Arizona in Tucson, is starting to reveal new information that is contrary to what was previously believed about the Arizona meteor crater. For example, originally it was believed that the meteor had been created by a solid meteor measuring around 40 meters in diameter and travelling at around 20 km per second. Tests within this vicinity have shown that both of these eventualities are extremely unlikely. The doctors now believe that the Arizona meteor crater was created by a ‘swarm’ of fragmented meteorite pieces that were travelling at a mere (if you can call it that) 11 km per second.
The Arizona meteor crater most certainly represents the possibilities that can arise from meteorites hitting us here on Earth. It was probably the first example of such a phenomenon and it has provided scientists with vital clues on what can and does happen as a result of such impacts. As we live on a planet that has constantly land-renewing geological processes, meteor impact craters are few and far between. The Arizona meteor crater is a clear and rather frightening reminder of the fact that such threats continue to exist from asteroids and meteorites in our own solar system and that we are just as prone to them as other planets that we can see with more abundant meteor impact craters.
Christopher L. Shelby, M.D.