Watch asteroid now streaking away
A small asteroid large enough to destroy a city came close enough to Earth this afternoon to destroy satellites, but not-so-close-up views were continuing to be streamed online.
Fortunately, the the 150-foot, 130,000-ton space rock, called asteroid 2012 DA14, was supposed to pass by without incident, although many wondered if hundreds of injuries and other damage in Russia from a meteorite might have involved a fragment or companion that tagged along.
[Update from NASA: ""According to NASA scientists, the trajectory of the Russian meteorite was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object. ... In videos of the meteor, it is seen to pass from left to right in front of the rising sun, which means it was traveling from north to south. Asteroid DA14's trajectory is in the opposite direction, from south to north."]
At 2:25 p.m., the asteroid reached its closest point, within 17,150 miles of our planet - less than a twelfth of the distance to the moon and well inside the orbits of geosynchronous satellites.
Nothing this large has ever been observed coming this close, according to a Bloomberg report.
About noon, images of the approaching asteroid from astronomers in Europe and Australia started being shown at www.ustream.tv/nasajpl2.
At first, the images showed a featureless bright spot moving fast against the still background of stars. Even nearly two hours later, the object appeared like a dot or a streak, instead of a closeup revealing a clear shape or even its little craters.
For a half-hour starting at 2 p.m., NASA provided live commentary along with images from observatories in Australia, thanks to very clear skies, at www.nasa.gov/ntv, as well as the link above.
After 2:30, more telescope feeds continued at www.ustream.tv/nasajpl2.
It's just a hint, thank goodness, at much-scarier, though remote, possibilities.
A much more massive "near-Earth object" named Apophis will come nearly as close - 19,400 miles - on April 13, 2029. If an object that size - about 1,000 feet across - collided with the planet, the explosion would be about 10 times more powerful than the biggest blast in the history of nuclear weapons testing, scientists estimate.
An asteroid measuring about 2 kilometers, or 1.25 miles, long could "produce severe environmental damage on a global scale," according to NASA.
The asteroid suspected of wiping out the dinosaurs 65 million years ago is estimated to have been about 10 kilometers, or 6.2 miles across.
As of this month, NASA's Near-Earth Object Program has found 861 asteroids at least 1 kilometer in diameter, but none of the calculated orbits suggest a collision course with Earth within the next 100 years.
The hope is that any potential rock of mass destruction can be found far enough in advance to develop a way to safely neutralize the threat. While Hollywood has dramatized the seeming simple idea of using nuclear weapons at the brink of doomsday, scientists know that a gentle nudge - perhaps even by a pelting with a plethora of paintballs to make the surface reflective enough to increase the pressure of sunlight - might be sufficient if applied early.
Contact staff writer Peter Mucha at 215-854-4342 or email@example.com.