Lunes 21 de Enero de 2002, Ip nš 10

Earth escapes brush with killer asteroid
Por Richard Stenger

The Near Earth Object brightened enough for even simple telescopes to spot just before it raced past our planet on Monday, only two times the distance of the moon, according to spaceweather.com, a NASA-affiliated Web site.

The range might seem like enough to breath easy, about 600,000 km (375,000 miles), but many scientists classify it as a relatively close call.

The asteroid, officially known as 2001 YB5, measures between 300 and 400 meters (1,000 to 1,300 feet) in width. If such a rock were to smash into the planet, it would unleash the same amount of energy as many nuclear bombs, astronomers estimate.

"The impact would be quite tremendous. It could essentially wipe out a medium-sized country," said Benny Peiser of the Royal Astronomical Society in Great Britain. "The environmental consequences would be regional but the social and economic consequences would be global."

Close encounters with giant space rocks are not uncommon. Asteroids comparable to 2001 YB5 could strike the Earth as frequently as once every 5,000 years, Peiser said.

In much rarer instances, boulders one kilometer or greater in size have smacked into the planet and snuffed out most life forms, much like the six-mile (10-km) long monster thought to have forced dinosaurs to exit stage left about 65 million years ago, according to scientists.

In the year 2027, an asteroid between one kilometer and mile in length is expected pass even closer than 2001 YB5. Having pinpointed its orbital path, scientists dismissed any potential of danger.

But later on, either asteroid could pose risks to the planet, along with countless rocks lurking in the shadows that have yet to be identified, astronomers warn.

What particularly troubles Peiser is that scientists only first spotted 2001 YB5 in early December. What if it had been heading on a collision course?

"That's not enough time for any initiatives for deflection. If we had 20 or 30 years' time, then we could develop a technology to deflect an object. With our current lacked of preparedness, we are helpless," he said.


  07/01/2002. CNN.