In light of what happened yesterday, this story is even more relevant now. It was written before the meteor event in Russia.
Asteroid 2012 DA14 makes its closest approach at 2:24 p.m. EST/1924 GMT today. One wonders if yesterday’s meteor in Russia wasn’t some parts of the asteroid fragmented in a deep space collision eons ago and in a similar trajectory hours ahead. It may also be simply coincidence. [UPDATE: NASA has issued a statement on this, see below.]
While politicians, their activist friends, and pundits caterwaul over a few tenths of a degree change in the global temperature over the last 100 years, with some Ehrlich-like nutballs even claiming it will cause extinction of humanity, today might be a good day to recognize a real extinction level challenge humanity faces.
A Warning From the Asteroid Hunters
The likelihood in this century of an asteroid impact with 700 times the destructive power of the Hiroshima A-bomb: 30%.
In the game of cosmic roulette that is our solar system, we just got lucky. Earth will get a very close shave on Friday, Feb. 15, when Asteroid DA14 passes just 17,000 miles from our planet. That is less than the distance from New York to Sydney and back, or the distance the Earth travels around the sun in 14 minutes. We are dodging a very large bullet.
The people of Earth also are getting a reminder that even in our modern society, our future is affected by the motion of astronomical bodies. The ancients were correct in their belief that the heavens affect life on Earth—just not in the way they imagined. Sometimes those heavenly bodies actually run into Earth. That is why we must make it our mission to find asteroids before they find us.
The last major asteroid impact on Earth was on June 30, 1908, when one about the size of an office building (140 feet across) slammed into Siberia with a destructive energy 700 times that of the atomic bomb dropped on Hiroshima. That asteroid devastated a region roughly the size of the San Francisco Bay area. Asteroid 2012 DA14, which will be passing over our heads on Friday, is about the same size as the asteroid that devastated Siberia’s Tunguska region. . . .
The chance of another Tunguska-size impact somewhere on Earth this century is about 30%. That isn’t the likelihood that you will be killed by an asteroid, but rather the odds that you will read a news headline about an asteroid impact of this size somewhere on Earth. Unfortunately, that headline could be about the destruction of a city, as opposed to an unpopulated region of Siberia. . . .
The chance in your lifetime of an even bigger asteroid impact on Earth—with explosive energy of 100 megatons of TNT—is about 1%. Such an impact would deliver many times the explosive energy of all the munitions used in World War II, including the atomic bombs.
Full story here at the WSJ.
Meanwhile, Barbara Boxer and friends want to create a tax to put billions into climate research while the asteroid program gets by on a shoestring. It only takes one asteroid to ruin your whole day, global warming, not so much.
NASA’s Spaceweather.com website writes:
At 9:30 am on Friday, Feb. 15th, asteroid 2012 DA14 will fly past Earth only 17,200 miles above our planet’s surface. This will put it well inside the orbit of geosynchronous satellites, closer than any asteroid of the same size has come since regular sky surveys began in the 1990s. Researchers speculate that Earth’s gravity might even cause seismic activity on the 50m-wide space rock. Click to view a computer simulation of the flyby, courtesy of NASA:
During the hours around closest approach, the asteroid will brighten until it resembles a star of 8th magnitude. Theoretically, that’s an easy target for backyard telescopes. The problem is speed. The asteroid will be racing across the sky, moving almost a full degree (or twice the width of a full Moon) every minute. That’s going to be hard to track. Only the most experienced amateur astronomers are likely to succeed. For the rest of us, NASA will broadcast the asteroid’s flyby on NASA TV.
Asteroid 2012 DA14 is about the same size as previous asteroids responsible for the Meteor Crater in Arizona and the Tunguska Event in Siberia. Unlike those objects, however, 2012 DA14 will not hit Earth. Even if seismic activity breaks the asteroid apart, there is no danger; the fragments would continue along the same non-intersecting path as the original asteroid.
UPDATE: (via NASA’s spaceweather.com)
It is natural to wonder if this event has any connection to today’s record-setting flyby of asteroid 2012 DA14. NASA has issued the following statement:
“The trajectory of the Russian meteorite was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object. Information is still being collected about the Russian meteorite and analysis is preliminary at this point. 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.”