Thread: Asteroid on collision course with Earth. Feb 2013

IMPACT PROBABILTY: 2.2e-04 = 1 in 4,550 chance.

Deadly asteroid 2012 DA14 bounds towards Earth out of the blue | THE TRUTH BEHIND THE SCENES

see also :

http://neo.jpl.nasa.gov/risk/2012da14.html

Bloody Mayan civil servants.

I'll be hoping for a huge strike on the EU parliament building when the house is sitting thereby finally putting an end to the fantasy world they are currently living in.

Mid has already pointed out, that the chance of that Asteroid hitting earth is one in 4,550 with the present measurements. The probability will be better calculated during the next few weeks, as more detailed measurements of the trajectory will come in.

The estimated energy is app. 2.2 Megatons of TNT. This is 2 orders of magnitude higher than the Hiroshima bomb. While it is a significant energy it is far from apocalyptic on a global scale. In the worst case an area the size if a major city would need to be evacuated.

I would be interested in the calculation of a resulting Tsunami in the likely case it will hit in the ocean.

«No, asteroid 2012 DA14 will not hit us next year | Bad Astronomy | Discover Magazine


For the tl;dr crowd, let’s get this out of the way right away: asteroid 2012 DA14 is almost certainly not going to hit the Earth next February. And by "almost certainly", I mean it: the odds of an impact are so low they are essentially zero. This does not rule out an impact at some future date, but for now we’re safe.

So what’s the story?
A small near-Earth asteroid was discovered in late February by astronomers at the Observatorio Astronómico de La Sagra in Spain, less than two weeks ago. Designated 2012 DA14, it’s estimated to be about 45 meters (150 feet) in diameter, and has an orbit that is similar to Earth’s.


Its orbit is an inclined ellipse, tilted a bit compared to Earth’s orbit around the Sun (the positions of Earth and DA14 are shown for August of 2012 — I picked that randomly to make the orbits clear), and it spends most of its time well away from our planet. However, the path of the rock does bring it somewhat close to the Earth twice per orbit, or about every six months. The last time it passed us was on February 16 – two weeks ago — when it was about 2.5 million km (1.5 million miles) away, equal to about 6 times the distance to the Moon. That’s usually about the scale of these encounters — it misses us by quite a margin.

February 2013: a close shave
Next year, on February 15, 2013, DA14 will actually get pretty close to Earth. It will pass us at a distance of about 27,000 km (17,000 miles) — well beneath many of our own orbiting satellites! To the best of my knowledge, this is the closest pass of a decent-sized asteroid ever seen before the actual pass itself.
However, let’s again be very clear: it will miss. In astronomical terms, 27,000 km is pretty close, but in real human terms it’s a clean miss.
[UPDATE: The rt.com article I linked below has changed substantively since I posted my own article here. They have attributed their quotations more clearly, and have taken out most of the more breathless rhetoric. I applaud them for doing so, though I wish they had been more clear in the first place.]
Unsurprisingly, though very irritatingly, I’ve seen a lot of websites writing about this as if the asteroid will hit. For example, rt.com has a very confused article about DA14 claiming it will somehow both miss us and hit us:

The rock’s closest approach to the planet is scheduled for February 15, 2013, when the distance between the planet and space wanderer will be under 27,000 km (16,700 miles). [...] With the asteroid zooming that low, it will be too late to do anything with it besides trying to predict its final destination and the consequences of impact.

Blechh. They write that in a way to make an impact seem likely, but that’s not the case at all! I’ve seen several other websites making similarly contradictory or confused claims (Note:I originally included this SFBay article as an example. It’s not confused, but by using the phrase "potentially fateful day" it struck me as exaggerating the fear). The rt.com article even comes right out and says "NASA confirms… [DA14] has a good chance of colliding with Earth". This is simply not true. I’ll note they don’t actually give a reference to that, so it’s not clear who, if anyone, actually said that, or where they got that information. Either way, it’s wrong.

The fuzzy future
So we’re safe for now. But what about future passes?
That’s harder to say. Predicting where an asteroid will be at some future time depends on a lot of things, including how good the observations are now and how long we’ve been watching it. When we observe an asteroid with a telescope, we can measure its position, but not with perfect accuracy. The Earth’s atmosphere blurs the image a bit, and other factors make it impossible to get an exact measurement. So we observe it many times, over as long a period as possible, to hammer down those uncertainties.
There will always be some small amount of fuzziness to the orbit of an asteroid, though, and the farther ahead in the future you look the bigger that fuzziness gets. For next year, we know the orbit of DA14 well enough to know it’ll miss, but for future orbits it’s harder to say.
As things stand, right now the JPL website lists the next close pass as February 2020, but we don’t know the orbit well enough at this moment to know how close that pass will be*. As things stand, the odds of an impact even then are very, very low (like, 1 in 100,000 — less than your odds of getting hit by lightning in your lifetime). We can’t technically rule it out just yet because, again, the orbit isn’t known well enough to look that far into the future. Of course, astronomers are observing the asteroid right now, and will continue to do so. No doubt we’ll have better orbital information pretty soon.

Keep watching the skies!
So again, because I can’t say this strongly enough: asteroid 2012 DA14 is not an impact threat for February 2013. However, we definitely need to keep our eyes on this guy to see if it poses a threat at some future date. If it does, then you can be sure you’ll be hearing about it from me, and from other websites too. But make sure you find reliable websites. Too many are too ready to breathlessly report this as doomsday when it’s anything but.
So, at least for February 2013, we can safely say:



* I’ll note the European NEO-DyS group uses different mathematical techniques, and they don’t even list that date as a near pass. Instead, they say it’ll be six months later, in September. Again, this shows that given our current observations of DA14, predicting its position that far in the future is very uncertain.

Originally Posted by Thaihome

make sure you find reliable websites. Too many are too ready to breathlessly report this as doomsday when it’s anything but.

Well, that discounts reading any links posted by ENT or Handsuman

Originally Posted by Neo

This is lower than the geosynchronous orbit kept by the Google Maps satellite

How can the Googlemaps satellite have a geosynchronous orbit? If it was geosynchronous then it would appear to be in the same spot all the time and would only be able to photograph one house.

The GPS satellites are geosynchronous but not the Googlemaps one.

I call bollocks on this fraud article.

Agreed.

@ Thaihome

Very good article. Some of that alarmist crap is unbelieavable. However with a potential for disaster of this magnitude I would not see a chance of one in 4550 as negligible. Even as an impact would not really cause a global scale extinction scenario. But no doubt the risk will get even smaller by the day when new position data come in and the orbit can be calculated with more precision.

Originally Posted by Latindancer

Well, that discounts reading any links posted by ENT or Handsuman

Big smile. Have a green.

Originally Posted by Looper

The GPS satellites are geosynchronous but not the Googlemaps one.

They are not, they are below geosyncronous. It is the TV and telecommunications satellites that are geostationary.

Besides they are not equatorial like the TV satellites but they have orbits passing near the poles to have satellites in position at any place on earth even in the high latitudes.

How will confronting it with paint work then?

Originally Posted by daveboy

How will confronting it with paint work then?

"Painting" or dusting the object with titanium dioxide (white) or soot (black) to alter its trajectory via the Yarkovsky effect.

Read up the Yarkowsky effect.

Excerpt:

Diurnal effect: On a rotating body (e.g. an asteroid) illuminated by the Sun, as on the Earth, the surface is warmer in the afternoon and early night, than in the late night and morning. The result is that more heat is radiated on the "dusk" side than the "dawn" side, leading to a net radiation pressure thrust in the opposite "dawn" direction. For prograde rotators, this is in the direction of motion on their orbit, and causes their semi-major axis to steadily increase, spiraling away from the Sun. Retrograde rotators spiral inward. The diurnal effect is the dominant component for larger bodies greater than about 100 m diameter.

Everything clear now?

Originally Posted by Thaihome

«No, asteroid 2012 DA14 will not hit us next year | Bad Astronomy | Discover Magazine

It's a good website.

Originally Posted by Latindancer

Originally Posted by Thaihome

make sure you find reliable websites. Too many are too ready to breathlessly report this as doomsday when it’s anything but.

Well, that discounts reading any links posted by ENT or Handsuman

green owed.

Originally Posted by Latindancer

Originally Posted by Thaihome

make sure you find reliable websites. Too many are too ready to breathlessly report this as doomsday when it’s anything but.

Well, that discounts reading any links posted by ENT or Handsuman

Yes, you should stick to your personal reference authority, "Popular Mechanics", which you claim to be a good scientific reference for your beliefs.

The damage could be worse if it rolls across the earth's surface and back out into the atmosphere. It doesn't have to hit the earth directly. This is my guess for the dinosaurs demise- the astreoid that flew back into space.

That asteroid is speculated to have hit the Yucatan plateau thus forming the gulf of Mexico.

I vote Mecca.

Originally Posted by Hampsha

I just suggest had there been another assteroid which never hit but skimmed,

Those kinds of assteroids are known as "haemorrhoids".
They make people bald.


From the Scientific Weakly interview: Vol 3, p23.

"Well, Grasshopper. Did you feel the haemorrhoid taking off your hair?"