The NEO Code -What Global Hotspots are Most at Risk Of Getting Hit by an Asteroid?
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September 08, 2009

The NEO Code -What Global Hotspots are Most at Risk Of Getting Hit by an Asteroid?

Asteroids “The threat of the Earth being hit by an asteroid is increasingly being accepted as the single greatest natural disaster hazard faced by humanity,” according to Nick Bailey of the University of Southampton's School of Engineering Sciences team, who developed the identifying program.

The team used raw data from multiple impact simulations to rank each country based on the number of times and how severely they would be affected by each impact. The software, called NEOimpactor (from NASA's "NEO" or Near Earth Object program), has been specifically developed for measuring the impact of 'small' asteroids under one kilometer in diameter.

Early results indicate that in terms of population lost, China, Indonesia, India, Japan and the United States face the greatest overall threat; while the United States, China, Sweden, Canada and Japan face the most severe economic effects due to the infrastructure destroyed.

The top ten countries most at risk are China, Indonesia, India, Japan, the United States, the Philippines, Italy, the United Kingdom, Brazil and Nigeria.

“The consequences for human populations and infrastructure as a result of an impact are enormous,” says Bailey. “Nearly one hundred years ago a remote region near the Tunguska River witnessed the largest asteroid impact event in living memory when a relatively small object (approximately 50 metres in diameter) exploded in mid-air. While it only flattened unpopulated forest, had it exploded over London it could have devastated everything within the M25. Our results highlight those countries that face the greatest risk from this most global of natural hazards and thus indicate which nations need to be involved in mitigating the threat.”

The team is also examining how the consequences of an impact change with increasing impact energy. Initial results indicate that a 100 meter diameter asteroid will predominantly cause localized casualties and damage across a few countries when impacting on either land or ocean. However, the consequences of a 200 meter diameter asteroid hitting the ocean increase significantly, with the generated tsunamis reaching a global scale. At 500 meters in diameter, almost any ocean impact will generate significant casualties and economic cost across the world.

As Stephen Hawking says, the general consensus is that any comet or asteroid greater than 20 kilometers in diameter that strikes the Earth will result in the complete annihilation of complex life - animals and higher plants. (The asteroid Vesta, for example, one of the destinations of the Dawn Mission, is the size of Arizona).

How many times in our galaxy alone has life finally evolved to the equivalent of our planets and animals on some far distant planet, only to be utterly destroyed by an impact? Galactic history suggests it might be a common occurrence.

The first this to understand about the KT event is that is was absolutely enormous: an asteroid (or comet) six to 10 miles in diameter streaked through the Earth's atmosphere at 25,000 miles an hour and struck the Yucatan region of Mexico with the force of 100 megatons -the equivalent of one Hiroshima bomb for every person alive on Earth today. Not a pretty scenario!

Recent calculations show that our planet would go into another "Snowball Earth" event like the one that occurred 600 million years ago, when it is believed the oceans froze over (although some scientists dispute this hypothesis -see link below).

While microbial bacteria might readily survive such calamitous impacts, our new understanding from the record of the Earth's mass extinctions clearly shows that plants and animals are very susceptible to extinction in the wake of an impact.

Impact rates depend on how many comets and asteroids exist in a particular planetary system. In general there is one major impact every million years -a mere blink of the eye in geological time. It also depends on how often those objects are perturbed from safe orbits that parallel the Earth's orbit to new, Earth-crossing orbits that might, sooner or later, result in a catastrophic K/T or Permian-type mass extinction.

Vredefort The asteroid that hit Vredefort located in the Free State Province of South Africa is one of the largest to ever impact Earth, estimated at over 10 km (6 miles) wide, although it is believed by many that the original size of the impact structure could have been 250 km in diameter, or possibly larger(though the Wilkes Land crater in Antarctica, if confirmed to have been the result of an impact event, is even larger at 500 kilometers across). The town of Vredefort is situated in the crater (image).

Dating back 2,023 million years, it is the oldest astrobleme found on earth so far, with a radius of 190km, it is also the most deeply eroded. Vredefort Dome Vredefort bears witness to the world’s greatest known single energy release event, which caused devastating global change, including, according to many scientists, major evolutionary changes.

What has kept the Earth "safe" at least the past 65 million years, other than blind luck is the massive gravitational field of Jupiter, our cosmic guardian, with its stable circular orbit far from the sun, which assures a low number of impacts resulting in mass extinctions by sweeping up and scatters away most of the dangerous Earth-orbit-crossing comets and asteroids

Posted by Rebecca Sato

Highly Recommended:

Pacific-Ocean-Sized Explosion On Jupiter Highlights Stephen Hawking's "Asteroid" Theory

Note: This post was adapted from a news release issued by University of Southampton.


 

Comments

Oops, in the ninth paragraph I think you meant to say "100 million megatons", otherwise Tsar Bomba was fully half as powerful as the KT extinction event! :D

Are we at risk?
electronic cigarette


Qev is right the impact power of a monster of 15-25Km diametre is thought to be NOT les that 100 Million megatons ....OR more ....depending on the impact angle.

That kind of an impact would generate a super E.L.E.

Tens of millions of Years for living species to recover and populate again the planet

God save us.

Regards to space guards

Regarding Hawking's idea about a 20km asteroid killing off life, there is the wilkes land crater in Antarctica that may have been caused by a 47km object, and led to the Permian extinction.

A 20 km object of silicate composition with a closing speed of 18 km/s would have an impact energy of 2.03 x 10^24 Joules, or 500 million Megatons.


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