The Thirty Foot Asteroid That Headed Toward Earth Unnoticed!

No one saw this bad boy coming. Not NASA. Not the Air Force. Surprise! It was the size of a small house and we had no warning at all.

bolide3.jpgSpace is a dirty place. There’s all sorts of interstellar junk flying around at breakneck speed. In our solar system Jupiter, the largest planet with the strongest gravity, gets hit most often.

Still, in terms relative to the age of our planet, the Earth gets hit all the time. Just the random dust and specks burning out in the upper reaches of our atmosphere add a few hundred million pounds of additional mass to Earth every day!

Sometimes the incoming rocks are large.

We don’t see much evidence because water and weather gradually heal our wounds. The pock marked surface of the atmosphere free Moon gives a more realistic impression of what really happens.

I mention this because a reasonably significant rock came pretty close to hitting the Earth a few weeks ago. I’m only hearing about it now–and I’m usually pretty up on these things.

Here’s NASA’s dispassionate reporting:

On October 8, 2009 about 03:00 Greenwich time, an atmospheric fireball blast was observed and recorded over an island region of Indonesia. The blast is thought to be due to the atmospheric entry of a small asteroid about 10 meters in diameter that, due to atmospheric pressure, detonated in the atmosphere with an energy of about 50 kilotons (the equivalent of 100,000 pounds of TNT explosives).

The Jakarta Globe said the explosion was loud enough that, “Locals at first thought it was an earthquake and ran out of their homes in panic.”

Well, yeah. A hundred thousand pounds of TNT would make quite a rumble.

No one saw this bad boy coming. Not NASA. Not the Air Force. Surprise! It was the size of a small house and we had no warning at all.

What little we do know of this incident comes because we monitor atmospheric noise while searching for nuclear tests. Again, it’s a surprise to me, but there is a network of “infrasound stations” associated with the Comprehensive Nuclear-Test-Ban Treaty Organization and they pinned it down.

In writing about this incident NASA scientists mention “an average impact velocity for NEAs of 20.3 km/s.” In other words, near Earth asteroids hit the Earth’s atmosphere at around 45,000 mph! That’s New York to Los Angeles in under four minutes!

Bottom line, those scary movies where asteroids plunge to Earth causing death and destruction… maybe they’re more science and less fiction than we think.

Asteroid 2004 MN4 – Who Invited Him?

Forget Hubble and all the other fancy astronomical hardware. Sometimes the most interesting finds come from more pedestrian equipment. Take the case of Asteroid 2004 MN4, discovered in June at the Kitt Peak National Observatory in Arizona.

The find was made by astronomers from the University of Hawaii taking part in an asteroid survey. That they found it was luck. Like most other minor space discoveries, the information was dissemenated and filed away. Then, on December 18, another spotting from Australia. After that dozens of other observations were made.

Now with multiple sightings it was possible to figure out the orbit of this chunk of space rock… a flying mountain if you will. It looked like it could cross the Earth’s orbit and it was assigned a probability, a mathematical chance, it would hit the Earth.

Excuse me? Hit the Earth? No, really. In fact, it was possible to come up with a date: April 13, 2029

That’s the bad news. The good news was the probability was only one chance in 233. NASA said that’s “unusual enough to merit special monitoring by astronomers, but should not be of public concern.”

Then a day or two later, with more observations and number crunching, the probability changed. Now it was one chance in 63. Interesting, but not alarming for an event 25 years in the future&#185.

It’s changed again.

On Christmas Eve a little gift from NASA scientists. Now it’s one chance in 45… a 97.8% chance of missing… or for my fellow pessimists, a 2.2% chance that April 2029 might be a really good time to run up your VISA with no intention of paying it off.

On the Torino scale of 1-10, this little gem has suddenly gone to a 4. It’s the first object to even make it to two!

A close encounter, with 1% or greater chance of a collision capable of causing regional devastation.

We’re talking about an object estimated to have a 1,250 foot diameter weighing 1.5 billion pounds&#187. When it hits the atmosphere it will be traveling at 27,000 miles per hour. That would create an explosion equivalent to 1,400 million tons of TNT!

For comparison, the nuclear bomb “Little Boy,” dropped by the United States on Hiroshima, Japan, had a yield of only about 0.013 megatons. The impacts which created the Barringer Meteor Crater or caused the Tunguska event in Siberia are estimated to be in the 10-20 megaton range. The 1883 eruption of Krakatoa was the equivalent of roughly 200 megatons.

So, we’re talking large, but this is not the magnitude of the event that took out the dinosaurs. It would still be devastating. Certainly it would reshape any land it impacted. A water impact would cause tsunamis of epic proportion.

Again, this is 25 years away and the calculations are likely to change. Still, if this is the first you’re hearing about it, aren’t you surprised there hasn’t been more play in the mainstream press?

The way this works is, someone, somewhere with the power to influence other news budgets (NY Times, Wall Street Journal, Washington Post, etc.) will run it and this story will pick up some traction. Until then, you heard it here first.

&#185 – I believe I have already scheduled teeth cleaning for that day.

&#178 – My conversion from 7.5e+10 kg to pounds is shaky at best. I’ll be glad to entertain corrections. No rush – we’ve got a few decades.