July 27, 2010

Earth At Risk Of Asteroid Impact In 2182

Scientists have discovered that a potentially hazardous asteroid might collide with Earth in 2182.

The scientists used two mathematical models in order to determine the chance of impact.

"The total impact probability of asteroid '(101955) 1999 RQ36' can be estimated in 0.00092 "“approximately one-in-a-thousand chance-, but what is most surprising is that over half of this chance (0.00054) corresponds to 2182," explains to SINC María Eugenia Sansaturio, co-author of the study and researcher of Universidad de Valladolid (UVA).

The research involved scientists from the University of Pisa, Italy, the Jet Propulsion Laboratory at NASA and INAF-IASF in Rome, Italy.

The asteroid is part of the Potentially Hazardous Asteroids (PHA), which are groups of asteroids deemed to have the possibility of impacting with Earth because of their orbits.  The asteroid was discovered in 1999 and is 1,837 feet in diameter.

The researchers performed 290 optical observations and 13 radar measurements in order to determine the asteroid's orbit.  However, a significant "orbital uncertainty" still exists because its path is influenced by the Yarkovsky effect.

The Yarkovsky effect slightly modifies the orbit of the Solar System's small objects because they radiate from one side the radiation they take from the sun through the other side.

The scientists reported their findings in the journal Icarus.

"The consequence of this complex dynamic is not just the likelihood of a comparatively large impact, but also that a realistic deflection procedure (path deviation) could only be made before the impact in 2080, and more easily, before 2060," said Sansaturio.

The scientists concluded: "If this object had been discovered after 2080, the deflection would require a technology that is not currently available. Therefore, this example suggests that impact monitoring, which up to date does not cover more than 80 or 100 years, may need to encompass more than one century. Thus, the efforts to deviate this type of objects could be conducted with moderate resources, from a technological and financial point of view."


Image 2: These are asteroids and comets visited by spacecraft. Credit: ESA, NASA, JAXA, RAS, JHUAPL, UMD, OSIRIS


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