Monday, June 27, 2011

Close Call With an Asteroid

Earlier today, (Monday, June 27 2011) at 17:01 UTC (1:01 PM Eastern US time) a small rock, roughly 10 meters in size, and named Asteroid 2011 MD, flew right past the Earth. In fact, if flew really really close to Earth, at about 12,400 km (7430 mi) from Earth’s surface. That distance is less than the diameter of the Earth itself! Or about 1/32 the distance to the Moon. But astronomers were dead on in determining that it would miss us.

Trajectory of near-Earth asteroid 2011 MD passing Earth on June 27, 2011. Credit: NASA/JPL Near-Earth Object Program Office.

It is actually fairly easy to determine where things are heading in space, or at least in the vicinity of our Solar System. The advent of Kepler's laws of planetary motion, along with Newtonian physics and some other neat tricks of the trade, and super computers for crunching the numbers, and really all that is needed is a velocity and a direction. So astronomers generally have a high degree of accuracy on object motion, there are perturbations every once in awhile, but this is usually because of some unseen gravitation interaction.

The biggest threat when it comes with asteroids of this size is the lack of warning. 2011 MD was discovered a mere 5 days before our encounter with it. Now, some people have been claiming that if an asteroid like this were to impact the Earth, it would send a tsunami across the planet twice. Which really just is not true. This was a loose, stony asteroid, like most asteroids, and would have broken up harmlessly in the atmosphere with no ground damage. If anything, it would be a hell of an early fireworks show. The worrisome ones are made up of iron, but aren't very common.

2011 MD on Monday, June 27, 2011 at 09:30 UTC. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South

Of course, it was also a great chance for amateur and professional astronomers to study an asteroid up close. Lately, it's been up to us to send probes and robots to check out asteroids, so it's nice for them to stop by for a visit once in awhile. There have been some great photos posted in this Universe Today article, and Spaceweather.com has a couple of images and movies up. Researchers have also used radio telescopes to study this piece of Solar System history.

Over at Bad Astronomy, Phil Plait wrote an excellent article and suggested that this is the kind of object that future space missions will be looking to explore. It would be relatively easy, easier than getting to the Moon, to put a man on an asteroid like this. Again, the biggest short fall being the lack of warning. But now that we know about this object, and know it will be about another 13 years before it comes this close again, maybe we can have a mission put together by then. Here's hoping to that great future.


19 comments:

AllenTesch said...

I heard about this just a day or so ago. I imagine if a big one happens, we won't know until after it does.

Lost.in.Idaho said...

I was waiting for the May Rapture sect to day "DOOMSDAY!!!" all over again.

Sorry, our math was wrong. And, um, the BIBLE says it would start with a meteor! Yeah, that's the ticket!

Jay said...

I also heard about this a few days ago and was wondering why there was so much attention on this asteroid when it would've just disintegrated on the off chance it hit the earth...

Aaron M. Gipson said...

Man, I am so glad I hear about this after the fact from a blogger I like than before the fact from Fox News or MSNBC...

Jim said...

Another close call that spooked someone but had no results, still cool to know something came that close though

The Angry Lurker said...

Good news about bad news, how big does an asteroid have to be to be a problem?

Atley said...

If we get sombody to land on an astroid that would be soooo cool! haha, like a fly landing on a bullet. lol. But glad we are not all dead from the astroid hitting us.

Astronomy Pirate said...

Well Lurker, that all depends on a few factors. If something that size was made of pure nickel-iron, a rare metallic asteroid, it would have caused the supposed tidal waves across most of the planet. It really does come down to Einstein's E=MC^2, the more mass and the faster it's colliding with the Earth, the more energy is released. Denser objects like nickel-iron asteroids would have more mass. For a stoney asteroid like this, you should start to worry at about half a kilometer in size.

The Dawg said...

Whoa, I did not even know. Well, we're all still okay, it seems. Good!

Bonjour Tristesse said...

Wow 5 days is not much warning at all. Kinda scary thought.

RedHeadRob said...

Damn! I missed it lol. As long as the world didn't end I'm fine though :D

Banacek said...

I have an image in my mind of an astronaut riding an asteroid like a bull.

A Beer for the Shower said...

Sorry, Harold Camping. This just isn't meant to be your year...

Alphabeta said...

Fireworks might have been nice.

Melanie said...

I was so excited to read about this on Friday. How do we miss that?

-E- said...

surely a tsunami wouldn't propagate around the americas?

DIYgamer said...

Crazy - I didn't know about this

Astronomy Pirate said...

@-E-, it probably wouldn't be that drastic, but it would have a global effect, much like a volcanic eruption can have a global effect.

Punky said...

Haha that's pretty crazy that such a minute path change could be devastating.

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