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Asteroid Apophis Just Got Bigger

Posted by samzenpus on from the a-little-chin-music dept.

astroengine writes "As the potentially hazardous asteroid makes closest approach to Earth today, astronomers using the European Herschel Space Observatory have announced something a little unsettling: asteroid 99942 Apophis is actually bigger than we thought. Herschel astronomers have deduced that Apophis is 1,066 feet (325 meters) wide. That's 20 percent larger than the previous estimate of 885 feet (270 meters). 'The 20 percent increase in diameter, from 270 to 325 m, translates into a 75 percent increase in our estimates of the asteroid's volume or mass,' said Thomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and lead scientist of the study. In addition, the space telescope has re-analyzed the albedo of the space rock, providing a valuable heat map of the object's surface — data that will improve orbital trajectory models."

3 of 182 comments (clear)

  1. 2029 approach by olsmeister · · Score: 5, Informative

    They're also saying that Apophis will pass within 36,000 km of Earth in 2029. Now that's not missing us by much.

    1. Re:2029 approach by SternisheFan · · Score: 5, Informative

      They're also saying that Apophis will pass within 36,000 km of Earth in 2029. Now that's not missing us by much.

      And that'll be about the right time for our space-tech to have caught up enough for us to be able to 'lasso' it. If we miss it then, by it's expected return in 2036 we'd better be able to control it. It seems to keep getting a little closer with each return orbit.

      From the above link:

      " The asteroid will return to Earth's neighbourhood again in 2036, but quite how close it will come then is uncertain, as the 2029 approach is predicted to alter its orbit substantially. Obtaining improved physical parameters for Apophis and its orbit is thus of great importance in being able to make better predictions of its future trajectory." Read more at:

    2. Re:2029 approach by Sowelu · · Score: 4, Informative

      For those who are hoping to see it, that distance puts it at two arcseconds wide (if my calculations are decent). This is roughly the same width in the sky as Neptune, or 900 times smaller diameter than our moon on an average day.