En una situación similar en 1998, con menos margen de maniobra y más osadía, los cientificos de la NASA de la pelicula Armageddon proponen varias maneras de evitar la colisión. Una de ellas resulta ser cubrir el asteroide con una capa de Mylar, un material extremadamente reflectante, para que actúe a modo de vela y haga que el viento solar desvíe el asteroide. La medida es rechazada por ser demasiado lenta, pero queda propuesta.

En el año 2008, justamente 10 años despues, en un congreso de astrofisica (centrado en la defensa contra cuerpos celestes) en Glasgow una estudiante de doctorado de la Escuela Superior de Ingenieria de Queensland (Australia) gana un premio por su ingenioso metodo para desviar el asteroide.

Lo que ella propone es cubrir la mitad del asteroide que apunta hacia el sol con una capa de Mylar para que actue a modo de vela y así el viento solar desvie su trayectoria lo suficiente para que no entre en una orbita de riesgo con la tierra.

¿Alguien ve la similitud?

Gracias por salvar el mundo, otra vez

Fuente: http://www.theregister.co.uk/2008/08/24/aussie_saves_earth_from_meteorite_collision_catastrophe/

Alain De Raclure et moi même concoctons un nouveau livre sur ce thème. La particularité de cet objet, outre qu'il sera bien évidemment entièrement sérigraphié, est qu'il sera réalisé en pop'up.

5 tableaux en papier découpé, plié, collé illustreront la fin des temps. On espère pouvoir le sortir début 2009, mais vu qu'on fait tout nous même à la main et que nous ne sous-traitons rien en Chine, vous comprendrez que tout cela prend énormément de temps.

Voici quelques photos d'un work in progress qui aspire toute notre énergie, comme 2012 emportera la vôtre:

]]> http://sg13.wordpress.com/?p=77 Sat, 23 Aug 2008 00:50:03 +0000 ce9999 http://sg13.pt-br.wordpress.com/2008/08/22/atlantis-goes-pay-per-view/ I became aware earlier today that the Sci Fi Channel, MGM and Stargate Productions have mutually decided to end the television run of Stargate: Atlantis at the end of its current season.

Really, I shouldn't be surprised about this, but I am. Does that mean I'm gullible? Well, yeah, but apparently I'm not gullible enough to qualify as a viewer that the Sci Fi Channel is interested in. They'll be replacing Atlantis with a new show, Stargate: Universe, that's specifically aimed at a "younger demographic."

People, "younger demographic" is simply marketing double-speak for "people who are more gullible and susceptible to advertisements." In other words, if this new show is aimed at you, it means the Powers That Be are assuming you are dumber and easier to sway than the current viewership of Stargate: Atlantis. Are you?

What's also disturbing about this is the way Atlantis itself is apparently being switched over to "pay-per-view" status. No, it won't be like regular PPV. You will actually have to go to a store and buy a DVD, or use whatever other means they might offer for getting your money (iTunes, for instance). But paying is paying, regardless of the means of delivery. Right now, you can watch Atlantis for free. Next year, you won't. What's more, I think they are doing this specifically because they believe Atlantis is at a popularity peak right now, that it can only go downhill from here, and furthermore, why should they continue to allow people to watch the show for free when they can replace it with a more profitable show which will probably cost less to produce, which will also appeal to a more desireable demographic, while still popping off the occassional Atlantis "movie" to rake in a few bucks on DVD sales to boot? To summarize, we, the viewers of Atlantis, are being ripped off precisely because we made this show as successful as it is.

What are my sources for these allegations? The changes have been documented with multiple articles on Gateworld, with the one of primary interest being "Wright: Atlantis is going out on top." This quote is of particular interest:

The decision to end Stargate Atlantis and jump to the movie format was made mutually by the SCI FI Channel, MGM, and Stargate Productions in Vancouver, executive producer Brad Wright told GateWorld today. Rather than canceling the show because of under-performance, the Powers That Be decided to go out on top while Atlantis is still popular enough to support the release of DVD movies.

See?

However, there is a potential positive side to this. While I've seen some concern expressed that the new Stargate: Universe show will end up being nothing more than the Stargate remake of Star Trek: Voyager (credit goes to Glenn H for that idea), it seems that the creators of the show are aware of some of the concerns I previously mentioned on this blog. An article entitled Stargate Universe Has A Go! states:

The show will be "a little more character-based, a little less rooted in a sci-fi mythology," co-creator Brad Wright told GateWorld. "It really does come down to characters and stories that are engaging, and that people want to see -- that they feel like they haven't seen before."

I'm not sure what Wright means about "rooted in sci-fi mythology", but I do like what he's saying about making the show more character-based, provided they don't end up with a bunch of squeaky-clean noobs like on the first couple of seasons of Star Trek: Voyager.

The other problem with that show's initial seasons was pretty simple too: the villians were boring. Remember the Kazon? No? I'm not surprised. Theoretically, they could have been interesting, but in practice, I groaned painfully at their every appearance on the show, and jumped for joy when Janeway and the crew finally got their asses out of that sector of the galaxy. The Wraith are somewhat better, but not a lot, and I'd consider them to be one of the primary flaws of Atlantis as a series. If Universe is to succeed, they really need to work on the bad guys. Look back at Apophis and Ba'al, and tell me I'm wrong.

I admit, I'm already wondering who they're going to cast on Universe. They're aiming for a younger demographic, so there'll probably be some 20-something male heartthrob in the lead. Zac Efron, anyone? He's 21 now. Heheheh. (I suppose I should shut up, before somebody gets the idea to do High School Musical In Space!....)

All in all, if Universe turns out to be a better series than Atlantis, then I'll probably be ok with this. There is one thing, however, which will disappoint me, even if that happens: Robert Picardo will only have one season to really show his stuff.

On the other hand, Atlantis has never been a top-tier show for me, especially when compared to these other shows, or even to its parent series, Stargate: SG-1. I don't think it has (so far) lived up to its potential, for a number of reasons. The main reason has to do with character, and this last episode just happened to bring the issue to the forefront of my mind.

In the episode, the question was raised whether Teyla, after the birth of her baby a couple of episodes previously, would be returning to "the team" [1]. As she hemmed and hawed about this question, I surprised myself by hoping that she would decide not to return, but instead would stay on the Atlantis station in some sort of advisory capacity or something. In other words, while I didn't want to see Teyla removed entirely from the show, the prospect of integrating a new team member seemed more interesting to me than simply having her carry on as before.

Why? Well, I really do hate to say this, but, over the first four seasons, and even so far this year, she just hasn't turned out to be a very interesting character. It seems like she hasn't changed one iota since the very first season, and frankly, I've virtually lost interest. This recent development with her partner and her having a baby, it reminds me of Will Riker cooking omlettes for Enterprise crewmates on Star Trek: The Next Generation so many years ago: an obvious attempt to add "dimension" to an otherwise flat character, without taking the apparently forbidden risk of having real character development. It's more tedious than interesting.

I could say similar things about many of the characters on Atlantis. Take Sheppard, for instance. The most interesting thing that ever happed to him was the one episode where he turned into a bug ("Conversion" in season two). Sure, this was an amusing story, and I imagine the ghost of Franz Kafka got a chuckle or two, but imagine how much better this episode could have played if only we had cared deeply about Sheppard as a person. "Ohmygawd! He's turning into a bug!!!!! This is horrible!!!!!!!!!!!!!!!!!1!!!!1!" But no—it was more like, "Ha! He's turning into a bug. Cool. This should be good. Hey—you got any more potato chips over there?" The writers have continued this pattern throughout the series. Once and a while, Sheppard is put through some sort of ordeal, presumably to give him "depth", but really they're just giving us more omlettes.

Carson Beckett is like this too. He's very likeable guy, but I admit I didn't feel much regret when he once again left the show at the end of last week's episode "The Seed", and I don't find myself caring very much whether they bring him back.

This flatness of character is a systemic problem with the show. To take the Beckett example a bit farther: His character was originally killed, it was only later that they pulled a Mr. Spock on him and brought him back. So let's compare his death to Mr. Spock's death. When Mr. Spock died at the end of Star Trek II: The Wrath of Khan, people cried. Seriously. I had to struggle with every fibre of my being to avoid crying openly in the theater (as a teenager, I would have felt like a complete ass if I cried, even if nobody noticed). When Carson Beckett died, well, I did feel bad. There may have even been a tear. I mean, he really is a nice guy, you know? His dedication to his profession is more than admirable—he's a genuine hero. However, while his death actually did suck, there wasn't much to it beyond that. This was not epic tragedy the way Spock's death was. Another good comparison would be to Daniel Jackson's death/ascension on SG-1. That really hurt, and the fact that he was supposedly still around as some sort of mystical energy-being was no consolation at all. It would have been the same for any member of the SG-1 team. I loved those guys! They were the best! However, with the possible exception of Rodney McKay, I have never had that depth of feeling for any character on Stargate: Atlantis. I doubt that I am the only one who feels this way. Why is this so? Because the characters just don't inspire that much feeling.

Replacing Teyla with a new team member might not have helped, of course. The last new person on the show was Dr. Keller, and where has she gone so far, as a character? Almost nowhere. Just as with Sheppard, the most interesting thing to happen to her is getting transformed into a bug. Ooops, I mean a giant tentacled creature. Whatever. (Does it really matter?) This happened in last week's episode, "The Seed," and, in fact, that story was even worse for Dr. Keller than Sheppard's bug-guy transformation, because in "The Seed", an episode revolving entirely around her, she spends the majority of her screen time unconscious!

I know full well that Jewel Staite can do more than what is being asked of her, too. Her completely delightful portrayal of Kaylee on Firefly was a highlight of that series—she stood out even though she had to compete with eight other well developed characters, and even though there were only fourteen episodes finished before the series was axed. But the character she's playing on Atlantis doesn't stand out much at all. I have to admit, if I wasn't such a Jewel Staite fan, I doubt Dr. Keller would have made any impression on me. I actually had to look up her name for this article because I couldn't remember it, in spite of the fact that she's been on the series for a whole season already.

However, I do have a couple of reasons to maintain hope. The first is that Dr. Keller is still fairly new. Even though she's been around a whole season, and even though her most significant moment during that time was her metamorphosis into a giant seaweed monster, it is still possible that some evolution could happen. She doesn't yet have four seasons of inertia holding her back like some of the other cast. The writers might go with idea of hooking her up with Dr. McKay, for instance. Anything involving Rodney McKay is probably a good idea, so that is a ray of hope. I also know that, if there's any shred of interest to be found in the Dr. Keller character at all, Jewel Staite will find it, if only the writers and directors give her the chance. She's also got star billing now, her face right up there in the main titles with all the others. Can this be an omen of things to come? I hope so.

I'm being pretty so critical of this show, but the truth is that I really do enjoy it. I wouldn't bother with all of this if I didn't care. But, to lighten this up a bit, I'll finish with a new development which I think is quite promising: Robert Picardo's addition to the cast.

Those faithful Trekkers who, like myself, suffered through the first couple of seasons of Star Trek: Voyager will probably recall Picardo's portrayal of The Doctor as one of the bright spots of that dreadfully dull early period in Voyager history. It's for this reason, and for his previous appearances on the Stargate shows, that I was very happy to see him included as one of the regular cast on Atlantis, even if it meant losing Samantha Carter.

(I know a lot of people are not happy about Carter leaving. However, as much as I like Carter, I'm not inclined to agree that her leaving the show is necessarily a bad thing. That, however, is a whole other topic, one which perhaps deserves a post of its own someday.)

Like Carter, Richard Woolsey comes with some predefined developmental background, although not nearly as much as Carter did. Woolsey was one of the more enjoyable antagonist guest characters on SG-1. He first appeared as a butt-clenching bureaucrat sent to sabotage the entire Stargate program through procedural means. It didn't work, not because he failed in his mission but because he changed his mind about the program. That right there was the beginning his evolution into someone interesting, and a sign that he wasn't going to be a one-dimensional villian like Senator Kinsey or Apophis. A one-dimensional villian can be entertaining, sure, but given a choice, I'll take a fully fleshed out antagonist just about every time (Peter Williams' excellent portrayal of Apophis notwithstanding).

Woolsey has some qualities similar to General Hammond, who also came to SG-1 in a somewhat antagonistic capacity (although Hammond was obviously never intended to be a real antagonist). Like Hammond, Woolsey can be swayed through reason, and will even occassionally break the rules for the greater good. He also has a hard-nosed side, so he can make the tough calls when he needs to. On SG-1, he abandoned his prejudices about the Stargate program, and ended up becoming a firm believer in it and the members of the SG-1 team (just as Hammond learned to trust the intelligence and integrity of Daniel Jackson, who he was pretty skeptical of at first). That sort of attitude change isn't just gratifying, it's interesting. Furthermore, unlike Carter, who's a character of action, thriving on movement and mission, Woolsey is entirely a thinker, a decider, a manager. Where Carter would carry out a mission, Woolsey would produce a mission statement. He's the kind of guy who could be your boss at that cushy desk job you want so much (and you'd be lucky to have someone as fair-minded as him, too). Perhaps most promisingly, although Woolsey does have very strong desk-jockey tendencies, it's already obvious that in order to be effective as the leader of the Atlantis team, he's going to have to grow beyond that, to acquire a bit of that movement and mission quality that Carter possesses.

It all sounds perfect, doesn't it? Everything is set up just so: We've got a moderately developed and fairly interesting character in a position where he'll have to develop some more if he wants to succeed at his job. The question now is, will the writers take this ball and run with it? We can only wait and see. So far, Picardo himself seems to be making the most of the opportunity he's been given. Witness the little moment in this most recent episode where Woolsey couldn't figure out how to get the conference room doors open. It wasn't just played as a matter of technical ineptitude, but also as an element of his larger struggle to earn the respect of the team. He's frustrated that the team doesn't yet respect him to the degree that he would like, but he's not simply throwing his authority around to gain that respect. He genuinely wants Sheppard and the others to respect him, and he wants to earn that respect fairly. He wants to deserve it, without compromising his authority, and this goal is important to him. Using the door-opening problem to illustrate this was a welcome detail, and a sign (I hope) that he will end up being more than just a cardboard cutout character. Yes, I'm definitely looking forward to seeing what happens with Woolsey.

-------
[1] By the way, why doesn't "the team" have a name? SG-1 had a name. Shouldn't Sheppard's team have a name too? Or at least an official designation of some kind???

O exceptie este asteroidul Apophis care, conform astronomului Sergey Barabanov de la observatorul Zvenigorod de langa Moscova, va trece suficient de aproape de Terra in anul 2029 pentru a fi vizibil cu ochiul liber. Aceasta apropiere va schimba traiectoria asteroidului, fiind chiar posibil sa il aduca pe o traiectorie care va duce la o ciocnire cu Terra in 2036.

Wel misschien niet, er werd een asteroide gespot die de aarde op minder dan 30 000 km zal passeren op 19 april 2036, als de wind verkeerd zit dan is het met ons gedaan.... Volgens NASA en andere instanties is de kans op een 'botsing' ergens tussen de 1/50 000 en 1/50(!), vergelijkbaar met de kans dat je in je leven door een bliksem wordt geraakt... Zoek eens op hoeveel mensen er jaarlijks door de bliksem worden geraakt...

Google het maar ne keer : Apophis en meteor...

En wij maar denken dat we veilig zitten....

Wie ich schon in einem früheren Eintrag berichtet habe, freue ich mich sehr auf das Wiedersehen mit Apophis. Doch der Auftritt war sehr klein. Im Prinzip waren alle Auftritte der Goa'uld, mit Ausnahme von Ba'al klein. Spaß hat es mir aber troztdem gemacht Apophis wiederzusehen.

Auser Apophis und die anderen Goa'uld gabs noch Auftritte von Jack O' Neill, Major Davis, President Hayes und General Hammond. Auf diese Charaktere hab ich mich auch sehr gefreut. Aber bei Major Davis z.B. war der Auftritt ebenfalls zu klein.

Nico Marquardt, un jeune allemand de 13 ans, a revu les calculs de l'agence spatiale américaine sur la probabilité de collision de l'astéroïde Apophis avec la Terre. Là où la Nasa obtient un risque de 1/45000, le jeune génie le multiplie par 100 à 1/450, en intégrant le facteur risque de collision avec un des 40.000 satellites en orbite dans les distances concernées. L'agence vient de lui donner raison.

via LCI

Commentaire de Brieuc :

Le mercredi 16 avril 2008 à 18:58

Et en fait c'est la Nasa qui avait raison ... O_o

via The register

Today is the 100th anniversary of the Tunguska Event.

Below a cut from The History Channel:

Be very afraid..........

Bilder (MGM)

NASA had previously estimated the chances at only 1 in 45,000 but told its sister organisation, the European Space Agency (ESA), that the young whizzkid had got it right.

The schoolboy took into consideration the risk of Apophis running into one or more of the 40,000 satellites orbiting Earth during its path close to the planet on April 13 2029.

Those satellites travel at 3.07 kilometres a second (1.9 miles), at up to 35,880 kilometres above earth -- and the Apophis asteroid will pass by earth at a distance of 32,500 kilometres.

If the asteroid strikes a satellite in 2029, that will change its trajectory making it hit earth on its next orbit in 2036.

To help myself put that in perspective, I translated the statistics as reported into lottery odds. Basically, the report is telling us that this bright young man was predicting that, thirty-one years minus two days in the future, an asteroid stands twice the chance of smacking into the Earth than I stood of winning $275 with New Jersey Lottery's Pick 3, as a result of banging into a satellite during a close encounter seven years earlier.

This is where the stink-o-meter went off. A satellite -- like, one of the ones the space shuttle carries as payload -- significantly altering the course of a reportedly 200,000,000,000 tonne (noting that tonnes are 10% larger than tons) hunk of iron? More importantly, the prize for a 1 in 1,000 bet is only $275? What kind of sucker plays those odds? But what about the bigger picture? If A) your odds of getting hit by an asteroid are better than your odds of winning the lottery, and B) your odds of getting hit by an asteroid will be 1 in 450 -- an low not seen since the Cretaceous–Tertiary extinction event -- on April 13, 2036, C) you'd have to be a dunce to not plunk down the kids' college tuition savings in every Mega Millions Jackpot you can find with a drawing that night.

Well, wouldn't you know it, respectable journalism had to go and ruin a good thing. If you're interested in the gory details, this fellow over at cosmos4u.blogspot.com does a nice job of corralling truth from fiction, including a link to NASA's NEO Program website that then links to this informative-if-low-tech animation:

Segnala link non funzionante

Edellinen suurempi mediakriittisyysmuistutus sattui Venäjän Pohjoisnapa-sukelluksen yhteydessä, kun Reuters välitti venäläisen tv-aseman lähettämää jutuntaustoituskuvaa todellisena kuvana meren pohjasta. Ja niin kuin me kaikki muistamme, olivat nämä taustoituskuvat peräisin Titanic-elokuvasta.

Enää nykypäivänä ei siis riitä, että uutisten toimittajana on jokin luotettavana pidetty taho, kuten vaikka Reuters tai AFP. Uutisiin tulee aina suhtautua kriittisyydellä, mutta se näyttäisi olevan kokoajan vaikeampaa, kun tarkan tiedon saatavuus ns. yleisissä medioissa alkaa olla yhä heikompaa. Lähtökohtaisesti voisi kai sanoa, että mitä erikoisempi tai järkyttävämpi juttu, sitä varmemmin se sisältää jotain epätarkkuuksia tai jopa väärää tietoa.  Vastuu on viimekädessä aina lukijalla.

Venäjän Pohjoisnapa-sukellukseen liittyvään kuva-sotkuun liittyen olen kirjoittanut seuraavat merkinnät:

• Missä kävitte Mir-1 ja Mir-2? (9.8.2007)
• Reuters, miksi seikoilet? (10.8.2007)

Dalam berita sebelumnya Nico Marquardt, siswa 13 tahun yang menyatakan Apophis akan menabrak Bumi dalam perbandingan 1:450. Berita yang beredar juga menyebutkan kalau Nico dan NASA sudah mencapai kesepakatan, bahkan NASA telah mengakui kalau ada kesalahan dalam perhitungan mereka.

Dari kantor Near-Earth Object (NEO) Program di NASA's Jet Propulsion Laboratory, Pasadena, Calif, dinyatakan kalau NEO tidak pernah merubah estimasi yang ada saat ini terhadap kemungkinan tabrakan Apophis. Apophis tetap akan memiliki kemungkinan tabrakan yang rendah dengan Bumi yakni 1 : 45000 di tahun 2036. Bahkan NASA khususnya dari NEO Program menyatakan para peneliti mereka belum pernah melakukan kontak maupun korespondensi dengan siswa tersebut.

Dalam berita sebelumnya, dinyatakan Nico Marquardt melakukan perhitungan terhadap kemungkinan tabrakan antara asteroid Apophis dengan satelit buatan sepanjang close encounter (pertemuan terdekat) degan Bumi pada tahun 2029.

Sayangnya pada tahun 2029 saat asteroid apophis tersebut mendekati Bumi, ia tidak akan melewati area di dekat sabuk utama satelit geosynchronous. Dengan kata lain kesempeatan terjadinya tabrakan dengan satelit buatan sangat jauh.

Karena itu pertimbangan skenario kemungkinan tabrakan dengan satelit, tetap tidak akan mempengaruhi kemungkinan tabrakan yang sudah diperhitungkan saat ini yakni satu berbanding 45000.

NASA khususnya dari programi NEO bertugas untuk mendeteksi dan mencari jejak asteroid dan komet yang melintas dekat Bumi. Mereka akan mencari dan menghitung jejak orbit si objek untuk dilihat apakah ia akan berbahay bagi Bumi atau tidak.

Sumber : Press Rilis NASA

L'asteroide 99942 Apophis non è probabilmente in alto nella vostra attuale lista delle preoccupazioni.
E d'altra parte, perché dovrebbe esserlo?
Questo sasso col nome di un cattivo di Stargate SG1 passerà dalle parti della Terra nel 2029, e stando alla NASA c'è appena una probabilità su 45.000 che colpisca il nostro pianeta estinguendo la vita come noi la conosciamo.

Ora, io sarò un tipo un po' troppo prudente, ma devo ammettere che 1/45.000 mi pare comunque un rischio elevato.
Un sei al Superenalotto ha una probabilità su 622.614.630 eppure c'è gente che gioco lo stesso....

Comunque il punto è che la NASA ha toppato.
Un tredicenne tedesco, Nico Marquardt, ha osservato che pur mancando la Terra, Apophis potrebbe colpire uno dei 40.000 mila satelliti, relitti ed altro pattume in orbita.
Ciò modificherebbe la sua orbita ed al passaggio successivo, nel 2036, Apophis colpirebbe la Terra con una probabilità di 1 su 450.

E qui non sono io che sono un po' troppo prudente.
1/450 è maledettamente poco, come margine di sopravvivenza.
E nel 2036 io avrei appena 69 anni.

Both NASA and Marquardt agree that if the asteroid does collide with earth, it will create a ball of iron and iridium 320 metres (1049 feet) wide and weighing 200 billion tonnes, which will crash into the Atlantic Ocean.

The shockwaves from that would create huge tsunami waves, destroying both coastlines and inland areas, whilst creating a thick cloud of dust that would darken the skies indefinitely.

Bello liscio.

E voi pensavate che il Berlusconi3 fosse un problema....

NASA a recunoscut eroarea. Stirea a aparut astazi, intr-un ziar german. Nico Marquardt a folosit datele Institutului de Astrofizica din Potsdam si a ajuns la concluzia ca sansele ca un asteroid sa loveasca Terra sunt de 1 la 450. Potrivit calculelor facute de specialistii NASA sansele ca asteroidul Apophis sa loveasca Terra erau de numai 1 la 45.000.

Asteroidul Apophis - care in greacă inseamna Distrugatorul - se va apropia cel mai mult de Pamant pe 13 aprilie 2029. Micul geniu in astrofizica a calculat ca, daca asteroidul se loveste de unul dintre cei peste 40.000 de sateliti artificiali, traiectoria ii va fi schimbata, asa ca ar putea lovi Pamantul peste 28 de ani, cand va trece din nou pe langa noi.

Atat Nico Marquardt, cat si specialistii de la NASA sunt de acord ca un asemenea impact ar insemna sfarsitul vietii pe pamant. NASA lucreaza deja pentru gasirea unor solutii de distrugere a asteroidului.

Seems that NASA wanted to reassure us that life as we know it would NOT end sometime in 2029.....said the odds are 1 in 450,000.

Now comes a German kid who says different.

NASA says they have rechecked, and he's wrong, but so were they. The odds are not as bad as the kid says, but worse than NASA originally said. Take a look at this map for a little perspective on how important the precise location of the decimal can be......

I say I'm moving to Montana.

Update: Shamelessly pinched from a comment on another blog:

By the way, it passes by the earth in 2027 on friday the 13th. If it hit's it will hit in the pacific ocean. So California may get wet. The energy content is said to be 26,000 Hiroshimas which is not that much but recent calculation suggest is more than enough to darken the earth.

Like, Montana might not be high enough......

Apophis, believed to be made up of iron and iridium, is supposed to have a possibility of striking the Atlantic Ocean.  The resulting tidal waves and dust cloud would wreak havoc on the population of the earth.  This asteroid is 1049 feet in diameter and weighs 200 million tons.  That's a big chunk of iron to be falling from the sky.

Even if there is actually a 1/450 chance of this object striking the earth, it is still a bit unlikely.  Not as unlikely as the NASA estimate of 1/45,000.  I have to wonder how sophisticated the calculations of a 13 year old are compared to NASA and all it's computers, but apparently the agency is taking the boy's work seriously.

Large objects have collided with earth in the past.  Anyone who looks at the moon knows what a meteor impact can do.  I'm not going to worry much about the possibility of asteroids striking the earth, there's nothing I can do about it so hey, why get upset?