Armogeddon: 2036

The modern astronomy becomes more and more socially relevant and publicly and politically correct. It is no longer a pure science but rather a branch of knowledge and data which can predict our fate and future. In the last five years its one of the most important achievements was a re-consideration of the asteroid formerly known as 2004 MN4 which lost its provisional designation and acquired its permanent number 99942 and name Apophis.

In Egyptian mythology, Apophis was associated with the ancient spirit of evil and destruction, a demon that was determined to plunge the world into eternal darkness. To be more precise, it is the Greek name given to the Egyptian demon Apep, who was the enemy of light and order as well as the personification of evil and chaos. Depicted as a giant snake, Apophis/Apep attacked the Sun God Ra as he made his way through the underworld during the evening hours. Solar eclipses were thought to be Apep’s few daytime attempts to swallow God Ra, who however always succeeded in cutting his way out of the snake’s belly. As the enemy of Ma’at, the ancient Egyptian concept of order and law, Apep represented the doom’s day for people. Astronomers reasoned this fitting name for such cosmic object based on a menace now hurtling towards the Earth from outer space.

Upon its discovery in 2004, Apophis was estimated to have a 2.9% chance of impacting the Earth in 2029. Additional measurements later showed there was no impact risk at that time from the 390-meter diameter object, identified spectroscopically as an Sq type similar to LL chondritic meteorites. Nevertheless it will approach dangerously close our planet in 2036 which is now estimated to be a 1 in 800 year event for an object of that size. NASA predicts that an impact from Apophis will free more than 100,000 times the energy released in the nuclear blast over Hiroshima and 250,000 times in the mysterious explosion of the Tunguska meteorite in Russia. Ten thousands of square kilometers would be directly affected by this humongous blast on a regional scale but the whole of the Earth would see the effects of the dust discharged into the atmosphere. It could be the Armageddon!

The Arecibo planetary radar telescope subsequently detected this asteroid at distances of 27-40 million km (0.192-0.268 AU) in 2005 and 2006. Polarization ratios indicated that Apophis appeard to be smoother than most NEAs at 13-cm scales. While trajectory knowledge of the object was substantially corrected by the Arecibo data, it is important to indicate a still substantial estimated chance of impact with the Earth in April 2036. With Apophis, probably, too close to the Sun to be measured by optical telescopes until 2011, and too distant for useful radar measurement until 2013, the underlying physics of its motion are thoroughly considered to better understand the hazard.