DYNASTY HVY

Interesting videos on the Russian meteorite.

Russia Hit By Spectacular Meteor Shower - FULL Video Collection (16 minutes in total) - YouTube
Dash Cam Footage Of Meteor in Chelyabinsk - 15th Feb 2013 - YouTube

Now imagine this happening over a major U.S city.




Ally

undflyboy06

It was traveling over 33,000 mph, weight about 10 tons (they think it was an Iron meteor), and was only 50 ft. wide. NASA says it exploded around 12-15 miles up with a force of 300-500 Kilotons.

Now, DA14, the Asteroid that passed Earth within 17,500 miles yesterday is around 150 ft. wide, half the length of a football field. I feel that would have been a global climate changer if it hit

We dodge a bullet on both, unfortunately there's around 100,000 more Asteroids out there the size of DA14 or larger.

Oblique

I don't think DA14 was big enough to cause a climate change if it hit Earth. In 1908 there was a larger asteroid that hit Russia estimated to cause a 5 - 30 megaton explosion and I don't think it affected climate change much, however, it did break up in the air. Tunguska event - Wikipedia, the free encyclopedia

It's really only a matter of time until we find we are on a collision course with another asteroid. The good news is that with today's technology we can probably attempt to divert the object and mitigate the risk.

atpwannabe

Our nation's defense system wasn't able to "pick up" that object moving at such an incredible speed and warn the Russians. Yet, radar is able to detect a C-172 in a no-fly zone and scramble two F-16's. Hmmm? IMO, something's amiss! IJS.



atp

UAL T38 Phlyer

How?

Movies would have you believe we can nuke it.

That would mean having a live "asteroid nuke" on the pad, all the time, ready to launch. You would need them on all sides of the globe, in case the asteroid was picked-up late, and your sole nuke was on the wrong side of the planet to make the intercept.

But the movies are wrong.

The primary cause of blast and destruction from a nuke is superheated air and shock wave. It is not the fireball.

(There's no air in space, so no shock wave).

The heat from a nuke would warm or melt some of the largely nickel-iron asteroid. But it wouldn't "blow it up."

Additionally, it takes a lot of booster to get objects in orbit. I've read it took 10,000 lbs on the launch pad to get one pound to the moon and back.

Nukes are heavy....you're talking a huge booster. And that is a lot of money to buy and maintain.

Not sure what "today's technology" you are talking about, but Star Trek "tractor beams" and "Shields" are still a long way off.

We are watching the No-Fly Zones, and ATC radar is pretty good at picking up a 90-kt Cessna (although not infallable).

What agency is training their radars towards space, 24/7?

There is nothing we can do to avert an asteroid or comet from hitting the planet without several years' worth of lead time, to build and launch a spaceship that could land on it, and fire an engine long enough to change its course.

Airhoss

Easy, put Timmy Martins on the job. You Give Timmy a C-172 a JATO bottle and sledge hammer and there isn't an asteriod in space that would survive!

UnderOveur

AND, his shoes would be shined, too!

11Fan

I found it mildly ironic that all eyes were on DA14 and this one over Russia pulls a Blue Angels Sneak Pass from behind.

USMCFLYR

Suppose to be these guys:
Near-Earth Asteroid Tracking (NEAT)

I remember a few astronauts (with the required credentials and scientific background) promoting the idea of a solar sail that seemed to be one of many ideas that was gaining some *steam* a few years back.
Asteroid impact avoidance - Wikipedia, the free encyclopedia

UAL T38 Phlyer

That's why I said it takes years....solar-sails, or ionic-engines are low thrust reaction-engines (rockets, if you like) that can alter the path of a rock if given enough time.

The thrust of these engines is on the order of micrograms, and therefore, it takes an incredibly long time to change the path by even a few milliradians.

But that also means intercepting it at incredible distances. That means an extremely powerful booster to put it in place (so that it would have the speed to get there quickly, instead of just coasting there as our Apollo spacecraft did to the moon). The intercept would be a one-shot deal, and at these speeds, would require a level of precision that probably isn't practical in space.

Further, you would have to detect these things at incredible range. 50-150 ft rocks aren't going to show up easily on telescopes when they are 3-4 years away from Earth. Radar? Power required goes up with the cube of the distance.

So, unless it is a huge rock or comet that we know passes every so many years, the rogue rock has no practical chance of being detected, deflected, or discumbobulated.