Asteroids – the inevitable rendezvous.

Regarding the threat of asteroids there is but one reality – that eventually the Earth will be hit by one. When that day comes a single factor will decide whether we survive or not. It is the size of the asteroid. Small objects of only several metres diameter can devastate major cities. Medium objects of up to a kilometre can devastate continents. The very largest asteroids can exterminate all life on Earth!

Unimaginable disaster.

The devastation caused would also depend on the location of the impact. If for instance a 2 kilometre asteroid were to hit the sea it would raise a tidal wave of unimaginable proportions – up to 10 kilometres high. This would naturally pour across continents washing away towns and cities like sand castles on a beach. If on the other hand the impact were on land it could, according to some scientists, release enough energy to remove the entire Earth’s atmosphere.

Close encounters.

An illustration of how pressing the fears are is illustrated by the rising number of close misses within recent times. In September 2000 for instance there were no fewer than five near misses from asteroids that sailed by with no more than a weeks warning.

More close shaves.

In 1991, a small asteroid passed within just 100,000 miles of the Earth. Two years later in May 1993, another asteroid missed us by just 80,000 miles. The year 1994 saw two close shaves with asteroids that hurtled by at a distance of only 100,000 miles! Although these distances may seem vast, in astronomical terms they represent no more than a bullet burn, the cosmic wink that sometimes separates us from outright disaster.

Tunguska.

In the early years of the 1900’s a fragment of a small meteorite devastated hundreds of square metres of a remote Siberian forest. A similar strike over a heavily populated city would produce millions of casualties in a catastrophe almost too fearful to contemplate.

Overdue impact.

The fact is that ever since the human race existed the danger from comets and asteroids has been an ever present reality. It is estimated that a major asteroid impact occurs every 25,000 years. Scientists believe the next strike is long overdue, and the unhappy truth is that we could be hit with absolutely no warning at all!

Early warning system.

Some attempt is now being made to set up an early warning system to detect planet threatening asteroids. However this is still a long way from knowing what to do if one were found to be on a collision course to hit us. If we had 10 years warning it is likely we might be able to deflect it with specially designed missiles. Unfortunately this capability would be severely shortened if the asteroid were detected within 2 – 5 years of impact. Even worse is the realisation that if we discovered an asteroid scheduled to hit us within 2 years there is certainly nothing we could do about it.Although scientists have basically cleared us from any danger from asteroid 2002 NT7, which originally had been reported as an impact hazard for the year 2019, a newer space rock has been spotted, which may pose a threat even sooner.

2014 Asteroid Hits Earth

At around 1.2 km in width, 2003 QQ47 is substantially smaller than 2002 NT7 (2km), but has been called “an event meriting careful monitoring” by astronomers. If an impact does occur, it could be on March 21, 2014.

Discovered on August 24, 2003, by the Lincoln Near Earth Asteroid Research Project (an MIT Lincoln Laboratory program funded by the United States Air Force and NASA) in New Mexico, 2003 QQ47 has been classified as a 1 on the Torino scale of impact hazards. Scientists are urging calm, however, saying the odds of a catastrophic collision are only around 1 in 909,000.

The orbit of this asteroid has been calculated on only 51 observations during a seven-day period and require further observations to determine if any danger does exist. It will be monitored closely over the next two months. Astronomers expect the risk of impact to decrease significantly as more data is gathered.

If it does strike Earth, the impact could have the effect of over 20 million Hiroshima style atomic bombs. As Billy Bob Thornton says in Armageddon, “It’s what we call a Global Killer….the end of mankind. Half the world will be incinerated by the heat blast…..the rest will freeze to death in a nuclear winter. Basically, the worst part of the Bible!”

Asteroids are rocks and debris which are the leftovers of the construction of our solar system nearly 5 billions years ago. Most are in a belt, which orbits the sun between Mars and Jupiter. However, the gravitational influence of the gas giant planets, like Jupiter, or an impact by a comet can knock these large rocks out of their safe orbit.

Needless to say, we will be monitoring this situation very closely.

Update:
Once again, the planet can breathe a sigh of relief. After making further observations of asteroid 2003 QQ47, astronomers now say there is no threat from this rock. It has been downgraded to a zero (0) on the Torin scale, which says, “The likelihood of a collision is zero, or well below the chance that a random object of the same size will strike the Earth within the next few decades. This designation also applies to any small object that, in the event of a collision, is unlikely to reach the Earth’s surface intact.”

While this particular asteroid appears to not be a threat to Earth at this time, the Near Earth Object Program and other agencies continue to monitor space for other threats. After all, it is a big universe, and there are a lot of asteroids and comets out there.