Asteroid Apophis Just Got Bigger

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."

Comments

SG-1

[madsci1016]

SG-1 Will take care of it no doubt.

Re:So...

[Anonymous Coward]

No, the chances we are all going to die are still 100%. The only question is when.

1 Earth Diameter Close Pass

[BoRegardless]

"In April 2029 the space rock will still make a very close pass with our planet, coming within 22,364 miles"

Being the skeptical engineer, I would say there is also a chance that on its multihundred million mile trip over the next decade and a half all it would take to nudge the orbit a slight amount to make the close pass a hit would be an encounter with another large object that affected its orbit ever so slightly...the wrong way.

That orbital perturbation is random & would simply not be predictable.

Re:1 Earth Diameter Close Pass

[girlintraining]

That orbital perturbation is random & would simply not be predictable.

Not exactly. It's passing by earth again in another 15 years or so -- and its orbit has to pass through a very small space in order for Earth's gravity to alter it just that tiny smidge so that over the following 15 years, that few thousands of a degree change due to gravitational pull will close that 22,364 mile gap. It has to be spot on -- if the vector is even slightly off, it'll either get slingshot out of the solar system (or into one of the outer planets), or into the Sun.

While you're right that the energy required to move the asteroid into a collision path is low, it has to be the precise amount, and at the precise vector. A random preturbation has a very low chance of being at both the correct energy level, and at the correct vector. And even many such random preturbations still wouldn't alter the orbit enough that if we looked for it on its next approach in a very narrow region of the sky, we couldn't find it. Which means we'll know its coming, and we'll have several years' warning to take action. I just hope they can clone Bruce Willis before then.