New Arecibo Data
Meteor Wayne Edit: Based on some user suggestions and recent developments, I have brought together the remaining Apophis threads......
Apophis is making a close earth pass in 2029, and then another close pass in 2036 with a non-zero chance of collision. If it does hit, it will strike in the northern Pacific and create a tsunami which will kill hundreds of millions, destroy major cities, and cause a worldwide dust cloud and 'winter'.
An accurate determination of Apophis' trajectory is key to understanding in the unlikely case that affirmative intervention is required to save modern civilization.
Here are two recent papers (paper one is a condensed version of the 20 page long Icarus paper) on Apophis trajectory calculations.
(I am sure some of you will find the asteroid mass information of the 32 largest known asteroids in Table 7 in the Icarus paper useful.)
The authors of the Icarus paper considered so many factors and error sources in trajectory determination - it is a very fascinating read. There are so many factors that are poorly understood which have huge effects on the location of Apophis in 2036.
The report includes looking for encounters with other asteroids (e.g., Apophis comes close to 144898 2004 VD17 in 2034, which you may remember is another NEO non-zero collision hazard), how to best conduct pre-2029 observations (radar is vital), and, briefly, mitigation possibilities.
Here are some:
In reply to:Trajectory predictions for asteroids are normally based on a standard model of the solar system that includes the gravity of the Sun, Moon, other planets, and the three largest asteroids.
However, additional factors can influence the predicted motion in ways that depend on rarely known details, such as the spin of the asteroid, its mass, the way it reflects and absorbs sun-light, radiates heat, and the gravitati - - - - - - - - - - - - - - - - - - - - - - I really, really, really miss the "first unread post" function.