Asteroid 2029 – only an exciting event in the sky or a real threat for mankind?

Asteroid Vesta
Asteroid 2004 MN4 also referred to as asteroid 2029, asteroid 99942 or Apophis asteroid had been first discovered in June 2004. This asteroid is about 300 meters wide and will come scarily close to Earth on Friday 13th of April 2029. Scarily close means the 2029 asteroid will fly past Earth only 30,000 km (18,600 miles) above the ground. For comparison, the average distance from Earth to the Moon is 384,400 km (238,855 miles), the geosynchronous satellites orbit at 36,000 km (22,300 miles). 

Asteroid Apophis is big enough to punch through Earth's atmosphere, devastating a region the size of France for example, if it hit any continent. Even more deadly it could cause widespread horrible tsunamis if it hit the ocean anywhere, 300 times more powerful than the 2004 Asian tsunami.

The chances for an impact on earth are estimated 1 in 240,000 by NASA, which sounds harmless, but some uncertainty remains. Asteroid 2029 has to pass a relatively small region of space known as a "keyhole" where Earth's gravitational pull would deflect its course just enough to change its way and guarantee a hit in 2036.
Asteroid IdaThe odds that asteroid 2029 could hit the earth are rated entirely reasonable by  Russian scientists, as they considered asteroid 2029 Apophis as the most serious threat to Earth as for now. The Russians plan to send a satellite with a radio beacon to near-Earth asteroid Apophis for finding out how big a threat of its collision with Earth really is. From a technical point of view the mission could be ready for implementation in 2015. On the other hand any influence on this object in its critical phase could do more harm than good.

As there are plenty of good scientific reasons for studying Apophis up close radar telescopes may be the safer choice. Ex Apollo astronaut Rusty Schweickart, who is deeply involved in studying potential threats from near-Earth objects, noted that there's are excellent opportunities for high-precision, Earth-based observations of the asteroid coming up in early 2013 and 2021. 

(Update Dec. 2012: More observations by scientists showed a probability of Asteroid 2029 passing through the keyhole is incredibly low, so the rating was eventually lowered to 0 these days.)
A few words why the asteroid is called Apophis. Tholen and Tucker, the two guys who discovered the near earth asteroid are fans of the TV series Stargate SG-1 and as anyone can suggest a name for an asteroid providing they have discovered it, they chose to name it Apophis. Btw, the word comes from Egyptian mythology and is the Greek name for Apep, the god of evil, darkness and chaos.

The chances of an asteroid approaching earth this close and with the same 2029 asteroid size is currently thought to occur at 1000-year intervals, on average.
During the last 10,000 years, an asteroid hitting Earth about 350 times with a size  between 50 to 100 meters in diameter. An object this size hit Tunguska in western Siberia in 1908, destroying 2,000 square kilometers of forest. The blast was at least 1,000 more powerful than the atomic bomb that destroyed Hiroshima in 1945.

Evidence of recent and prehistoric impact events:
65 mil. Years – Yucatan impact and extinction of the dinosaurs.
52,000 years - Lonar crater lake in India.
50,000 years - Barringer Crater in the USA.
10,000 years - Rio Cuarto craters in Argentina.
5,000 years - Henbury craters in Australia.
3,500 years - Kamil craters in Egypt.
2,700 years - Kaali craters in Estonia.
2500 years - Chiemgau in Bavaria, Germany.
500 years  - Shanxi Province in China.
100 years  - Tunguska in Sibiria.

We now know that the majority of asteroids that we see in our night sky come from an asteroid belt that exists between Mars and Jupiter. Another region of large objects further out is called the Kuiper belt and one outside our solar system called the Oort cloud.

As there are many near-Earth objects flying around in our solar system what is the definition of asteroid? Unfortunately there has never been a formal definition, as it can be any small Solar System body. You can distinguish an asteroid and a comet because a comet shows a coma due to the sublimation of its ices by solar radiation. A meteoroid is anything smaller than 10 meters in diameter.

While the asteroid 2029 chances to hit earth may small, there are other threats out there. Next year on February 15, 2013 asteroid, 2012 DA14, will miss the planet by 26,900 kilometers, which is even closer than Apophis, with the “Tunguska” size between 40 and 95 meters in diameter. Another candidate is 2011 AG5m, 140 m in diameter, with a given chance of 1-in-625  of hitting Earth on Feb. 5, 2040.

Hopefully Friday the 13th will be the lucky day where we have the chance to observe asteroid 2029 with the naked eye, from a save distance. Nobody in recorded history has ever seen an asteroid shining like a 3rd magnitude star even through city lights.

Asteroid pictures: 1. Vesta, 2. Ida

get more Asteroid News:
NASA Jet Propulsion Laboratory
California Institute of Technology
La Cañada Flintridge, CA, United States
Phone +1 818-354-4321

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