|An illustration of asteroid Apophis nearing Earth. NASA officials |
insist that, contrary to the dire fears of Russian scientists,
Apophis will not hit our planet in 2036.
The Lyrids are one of the oldest known showers, creating a light show usually seen easily from Earth -- and completely harmless.
Until recently, though, plenty of sky watchers thought Earth would now be starting a 25-year countdown to planetary holocaust -- April 13, 2036, when the 270-meter-wide asteroid dubbed 99942 Apophis would hammer our home world with the force of two Krakatoas. Not enough to crack Earth like a rotten coconut, but enough to ruin a lot of people's day.
Today, however, NASA officials are more likely to grumble in private that Apophis is the cosmic clod that just won't go away. "We are confident it will be a non-issue," said Don Yeomans, manager of NASA's Near Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif.
Apophis looms in the public's imagination for good reason. In February, Russian scientists made a more-dire-than-necessary prediction: that Apophis, named for the Egyptian god of Chaos, would blast the planet to borscht in 25 years.
Perhaps in the grip of Apophic apoplexy two years earlier, Russia had announced mission plans with the intent to deflect the rock away from Earth. That approach was criticized for fear it might actually have the opposite effect.
Also, the French proposed sending a group of solar sails toward Apophis to reflect radiation at it, hoping to change its course.
Even more confusing is the possibility that, in April 2029, Apophis -- with a similar orbit to Earth's around the sun -- might pass through a "gravitational keyhole," a section of space subject to concentrated gravity about twice its size. In theory, that could alter its orbit enough to swing it back to hit Earth in 2036.
"Earth's gravitational tugs are just enough to modify [Apophis'] orbit," Yeomans told AOL News, but he added that the chances of this actually happening are 1 in 250,000 and likely to get smaller.
That level of risk is in between dying in a flood -- 1 in 175,803 -- and getting blown up by fireworks, 1 in 386,766 (death by gunshot risk is 1 in 306, and that hasn't prompted the repeal of the Second Amendment, after all).
Apophis doesn't even rate a highlighted color on the Near-Earth Object Program's risk charts. But before you cross astro-death off your list of things to worry about, think about this: NASA's budget request for 2012 for patrolling the skies has increased fivefold, from $4 million to $20 million, though the number is subject to change in current congressional debates.
"We have far more immediate concerns than asteroid impacts," Yeomans said. "But they are the only natural disaster I know of that could quickly wipe out a civilization."
While an asteroid hit is on the scale of bad things happening, it's highly improbable. "They are high-consequence events that we need to pay more attention to than we have been," Yeomans added. "We don't need to mount an emergency campaign, but I think we should increase our search efforts."
Scientists have discovered about 900 potentially threatening space objects over 1 kilometer in size or larger -- that's 0.6 miles, about the distance you could go in a 10-minute walk.
However, Congress recently revised the parameters for what it considered a hazardous space object down to a diameter of 140 meters -- about 1 1/2 times the size of a football field. That's big enough to cause a tsunami, depending on what the object is made of: Comet debris can be large balls of porous fluff, while others are slabs of solid iron or piles of rubble held together by gravity.
Yeomans estimates NASA is only about 20 percent of the way to tracking these smaller but potentially deadly objects. It wants to reach 90 percent to relieve an element of worry from the public consciousness.
"There are an extraordinary number of objects in space we need to track," Yeomans said. "For years, we were blissfully ignorant."(aol.com)