Close Call: Asteroid 2009 DD45 Passes Earth

[waht]

Wow! millions of people could have died yesterday, if perhaps some random intergalactic tug pushed the sucker on a trajectory towards earth.

http://news.bbc.co.uk/2/hi/science/nature/7921279.stm

An asteroid which may be as big as a ten-storey building has passed close by the Earth, astronomers say.

The object, known as 2009 DD45, thought to be 21-47m (68-152ft) across, raced by our planet at 1344 GMT on Monday.

The gap was just 72,000 km (44,750 miles); a fifth of the distance between our planet and the Moon.

It is in the same size range as a rock which exploded over Siberia in 1908 with the force of 1,000 atomic bombs.

 

[hypatia]

Whewwwwwwwie that was close.

 

[Monique]

That IS close

 

[Evo]

We are only aware of a fraction of the NEOs out there.

 

[turbo]

We are only aware of a fraction of the NEOs out there.

And if they sneak up up on us from a trajectory that takes them near the Sun and sail in, there is very little that we can do. No visual warning from the types of surveys that try to identify these rascals.

On a side note, what would happen if a paranoid culture with nuclear weapons and some favorite enemies was the impact-point? Such an impact could easily trigger WWIII if it were misinterpreted. The lack of EMP, residual radiation etc, would be good signs that the cause of the destruction was natural, but with some militaries geared toward hair-trigger responses, we could have been in a LOT more trouble than that posed by an asteroid impact.

 

[turbo]

Another side-note. Anybody here a fan of B-5? What was the weapon of choice in the siege of the Narn home-world? Mass-drivers, propelling large masses (asteroids/whatever) toward the planet, and letting the planet's gravity do the rest. Destroy the infrastructure of the society, and move in and take it over with no residual radiation, etc. Harlan Ellison (science consultant for B-5) is no dummy.

 

[Astronuc]

For more details, see http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009 DD45;orb=1

Even closer - http://neo.jpl.nasa.gov/news/2008tc3.html

 

[Ivan Seeking]

On a side note, what would happen if a paranoid culture with nuclear weapons and some favorite enemies was the impact-point? Such an impact could easily trigger WWIII if it were misinterpreted. The lack of EMP, residual radiation etc, would be good signs that the cause of the destruction was natural, but with some militaries geared toward hair-trigger responses, we could have been in a LOT more trouble than that posed by an asteroid impact.

This is a known issue for the US. Hopefully the other nuclear powers have considered this scenario.

 

[LowlyPion]

Scientists at the Siding Spring Observatory in Australia spotted 2009 DD45 and began tracking it in late February when it was about 1 million miles away.

http://www.google.com/hostednews/ap/article/ALeqM5iMRlXoAOKgOWrgy2Iux54E-dmD8QD96NJ2H81

With only a couple of weeks notice ... zowie.

Don't let Brownie lead the evacuation.

 

[Art]

Are these small asteroids escapees from the asteroid belt or do they come from the Oort Cloud?

 

[mgb_phys]

On a side note, what would happen if a paranoid culture with nuclear weapons and some favorite enemies was the impact-point? Such an impact could easily trigger WWIII if it were misinterpreted.

They should be paranoid - http://en.wikipedia.org/wiki/RIM-161_Standard_Missile_3
No explosive residue, no radiation, just a big smoking hole in the ground where your presidents palace used to be.

 

[alseth]

Are these small asteroids escapees from the asteroid belt or do they come from the Oort Cloud?

They are mostly members of Apollo or Athen groups (aka earth-crossers asteroids). But the possibility that we will got hit by an object which was grav. expelled from other groups such as the asteroid belt is not zero either.

 

[waht]

This is a known issue for the US. Hopefully the other nuclear powers have considered this scenario.

yea, I think every nuclear weapon can be traced back to the country of origin based on isotopic ratios, if I'm not mistaken. And the angle at which the asteroid descends will also leave a specific signature in the aftermath.