How dangerous are near-Earth asteroids? 5 key questions answered.

On Feb. 15, asteroid 2012 DA14, discovered a year ago, cleared Earth by a scant 17,200 miles. The same day, a smaller, unrelated asteroid that no one saw coming exploded 12 to 15 miles above Russia’s Chelyabinsk region. Events that day highlight the risk that near-Earth objects (NEOs) can pose – although to some extent, humans can counter them.

2. How many have been detected?

Courtesy of NASA/Reuters
The path of asteroid 2012 DA14's approach to earth.

Initially, astronomers hunted for objects half a mile wide or wider and found 862 – about 95 percent of all NEOs thought to be in this size class. Since 1995, they have counted smaller objects as well and have found a total of 9,730.

Of them, 1,379 are potentially hazardous, according to specialists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. These objects are at least 150 feet across, and their orbits bring them 7.5 million miles or closer to Earth. Some 155 of the potentially hazardous objects found so far are at least a half mile wide.

In 2005, Congress charged the National Aeronautics and Space Administration with locating and tracking objects 500 feet across or larger by 2020. Progress has been slow. NASA’s NEO budget stayed flat at about $4 million between 2002 and 2010, although it was increased to $20.5 million for fiscal year 2012.

The smaller the NEO, the more of them there are. Astronomers figure they’ve spotted less than 1 percent of all the NEOs 100 feet or larger – which still can pack a wallop.

2 of 5

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

You've read  of  free articles. Subscribe to continue.