Tag: asteroid impacts

"Armageddon" had bad science. Shocker, I know.

By Phil Plait | September 7, 2012 7:00 am

I do so love to make fun of the movie "Armageddon". I know, it’s such an easy target, but still.

I talk about the movie when I give public lectures about asteroid impacts, because a lot of people have seen it – so it’s a nice common point of contact – and because it really goes out of its way to get so much stuff wrong.

The premise of the movie is that a giant asteroid is going to hit the Earth and wipe out all life. I’ll skip a vast amount of silliness and get to the thing that really made me laugh out loud when I first saw the flick: to prevent the impact, astronauts plant a nuclear bomb below the surface and detonate it. This splits the asteroid in half, and (SPOILER ALERT!) the two pieces are flung apart at sufficient velocity that they pass our planet on either side, missing us, and the world is saved!

Yay?

Well, not so much. I saw the movie when it came out in 1998, and after I got home from the theater – and after the Tylenol kicked in – I did a little math. We know how big the asteroid is, and what it’s made of – that gives us the mass (and therefore the mass of each half after it’s split). We also know how rapidly it’s approaching the Earth, and how far it was from the Earth when the bomb went off. That then can be used to figure out how fast the two halves separated (they had to separate by at least the Earth’s diameter to miss us).

An object in motion has energy, called kinetic energy. It depends on the mass of the object and its velocity – the more massive it is, or the faster it moves, the more kinetic energy it has. In the case of the Armageddon asteroid, the two halves got their kinetic energy from the bomb, so by calculating the kinetic energy of each piece you can find the explosive yield of the bomb.

I did that. The bomb would have exploded with roughly the same energy output as the Sun. In other words, it would have been a 100 billion megaton bomb. Yikes.

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CATEGORIZED UNDER: Astronomy, Geekery, Humor

Privately and publicly looking for Earth-threatening asteroids

By Phil Plait | June 28, 2012 12:53 pm

[Note: In the interest of full disclosure, I am friends with many of the folks on both teams described below. I have tried to be scrupulously fair to both missions, and to be honest - as I say below - the best thing to happen would be for both missions to be locked, loaded, and looking for potentially hazardous rocks.]

The B612 Foundation is a group of scientists, astronauts, astronomers, and engineers who have come together to do nothing less than literally save the world: they want to find and deflect asteroids that can potentially hit the Earth. While really big asteroids are rare — after all, the one 10 km (6 miles) across that wiped out the dinosaurs only hits Earth every few hundred million years — smaller ones in the 100 meter range are far more common and can still do devastating damage. Even one just 50 meters across (smaller than a football field) can impact and explode with the yield of millions of tons of TNT. That’s in the range of the biggest nuclear weapons ever detonated.

Finding these asteroids is notoriously difficult. They’re small and dim, and sometimes only discovered once they’ve already passed us! The best way to find them in large numbers is to launch a space telescope to survey the sky, tuned to the infrared where these asteroids are far brighter and easier to spot.

Today, B612 made a big announcement: they want to build just such a mission. They call it Sentinel, and it will be the first privately funded deep space mission ever launched. Built by Ball Aerospace and launched on a SpaceX Falcon 9 rocket, it will be placed into a Venus-like orbit, giving it a good view of the volume of space where these asteroids prowl:

[Click to chixchulubenate.]

The plan is to raise the money philanthropically, like museums do: donations from private funders. Observatories have long been funded this way, and the proposed cost of a few hundred million dollars is roughly on par with many civic projects. Their target launch date is 2017 to 2018, and the mission will last about 5 years.

Interestingly, a group of scientists and engineers with NASA/JPL is planning a similar mission! Called NEOCam (for Near Earth Object Camera), it’s based on previous missions like WISE and Hubble.

Sentinel and NEOCam have many similarities: they both use a 50 cm or so telescope, both are tuned to infrared, and both will launch into orbit to get a better view of potentially threatening asteroids. Read More

If the Mayans were right, it was probably about Internet comments

By Phil Plait | May 15, 2012 6:55 am

A little while back, I was at Utah State University to give a public talk about the threat from asteroid impacts and what we can do to stop them (PLUG ALERT: if you want me to come talk at your venue, my agent would love to hear from you).

While I was there I was interviewed by Utah Public Radio, and that interview is online.

I was also chatted up by the local TV station, KSL. I think it went OK, and they put it online as well:

[You may have to refresh this page to get the video to load.]

While I rather wish I had stated succinctly that even the basis of the "Mayan 2012 doomsday" nonsense is itself a gross misinterpretation of Mayan history, culture, and calendar, I think I was pretty clear. I have to walk a fine line sometimes: debunking crap doomsday scenarios like 2012 while also warning of real dangers like asteroid impacts… while neither over- or understating that danger. It’s a delicate balance.

A balance, I’ll note, which is apparently completely lost on some of the commenters on the KSL website who are saying I’m totally wrong and that the doomsday is coming in December [Note: I checked just before posting this, and most of the really over-the-top comments have been deleted, and I thank the forum moderators for that]. The sheer blind eye some have toward reality is stunning.

I know some people have deep beliefs they hold true, and are willing to deny what’s right in front of their face if they have to. I also know it’s the Internet out there, where people don’t read past the first line or watch a video past the first few seconds. Still, the denial and — to be blunt — dickery is breathtaking. One person actually said they hoped the Universe kills me so they don’t have to listen to my "drivel" [that was one of the comments deleted, BTW].

Of course this isn’t the first time I’ve had someone wish me dead, or that I’d shut up. Duh. But what I find fascinating is the irony. One complaint I hear about critical thinking is that it takes away hope, takes away beauty, and replaces them with despair and the ugly nature of reality. And yet here we see people shredding their critical thinking to hold fast to a doomsday scenario that is as ugly as it is hopeless.

If they actually applied a bit of skepticism, they’d see the 2012 doomsday garbage for what it is. But they cleave unto it as fervently as a drowning man to a life preserver.

I don’t think I have anything particularly profound to add to this; I’m just shining a light on it for you to see. Be aware of this, and always remember people’s ability to be paradoxical and completely embrace a nonsensical danger while denying the real one.


Related Posts:

- Re-cycled Mayan calendar nonsense
- My asteroid impact talk is now on TED!
- MSNBC interview: 2012, the year the Earth doesn’t end. Again.
- Betelgeuse and 2012
- Giant spaceships to attack December 2012?
- No, a pole shift won’t cause global superstorms

Breaking: Private company does indeed plan to mine asteroids… and I think they can do it

By Phil Plait | April 24, 2012 12:01 am

Planetary Resources, Inc. is not your average startup: its mission is to investigate and eventually mine asteroids in space!

Last week, the company issued a somewhat cryptic announcement saying they “will overlay two critical sectors – space exploration and natural resources – to add trillions of dollars to the global GDP”. I predicted this meant they wanted to mine asteroids, and yes, I will toot my own horn: I was right. They’re holding a press conference Tuesday morning to officially announce they’re going asteroid hunting.

The company had a pretty fierce amount of credibility right off the bat, with several ex-NASA engineers, an astronaut, and planetary scientists involved, as well as the backing of not one but several billionaires, including a few from Google… not to mention James Cameron. The co-founders of Planetary Resources are Peter Diamandis — he created the highly-successful X-Prize Foundation, to give cash awards to incremental accomplishments that will help achieve technological breakthroughs, including those for space travel — and Eric Anderson, X-Prize board member and Chairman of the Board of the Space Spaceflight Federation.

These are very, very heavy hitters. Clearly, they’re not screwing around.

So what’s the deal?

 


Step 1

I spoke with Planetary Resources President and Chief Engineer Chris Lewicki on the phone Monday. He has an excellent pedigree: Lewicki was Flight Director for the NASA’s Spirit and Opportunity Mars rover missions, and also Mission Manager for the Mars Phoenix lander surface operations. So when he says he’s confident the company can and will succeed, I’m willing to listen.

“This is an attempt to make a permanent foothold in space,” he said. “We’re going to enable this piece of human exploration and the settlement of space, and develop the resources that are out there.”

The plan structure is reminiscent of that of Apollo: have a big goal in mind, but make sure the steps along the way are practical.

The key point is that their plan is not to simply mine precious metals and make millions or billions of dollars– though that’s a long-range goal. If that were the only goal, it would cost too much, be too difficult, and probably not be attainable.

Instead, they’ll make a series of calculated smaller missions that will grow in size and scope. The first is to make a series of small space telescopes to observe and characterize asteroids. Lewicki said the first of these is the Arkyd 101, a 22 cm (9″) telescope in low-Earth orbit that will be aboard a tiny spacecraft just 40 x 40 cm (16″) in size. It can hitch a ride with other satellites being placed in orbit, sharing launch costs and saving money (an idea that will come up again and again in their plans). This telescope will be used both to look for and observe known Near-Earth asteroids, and can also be pointed down to Earth for remote sensing operations.

I’ll note Lewicki said they expect to launch the first of these telescopes by the end of next year, 2013. They’re already building them (what’s referred to as “cutting metal”). They could launch on already-existing rockets — an Atlas or Delta, for example, Europe’s Ariane, India’s GSLV, or Space X’s Falcon 9.

After that, once they’re flight-tested, more of these small spacecraft can be launched equipped with rocket motors. If they hitch a ride with a satellite destined for a 40,000 km (24,000 mile) geosynchronous orbit, the motor can be used to take the telescope — now a space probe — out of Earth orbit and set on course for a pre-determined asteroid destination. Technical bit: orbital velocity at geosync is about 3 km/sec, so only about an additional 1 km/sec is needed to send a probe away from Earth, easily within the capability of a small motor attached to a light-weight probe.

Many asteroids pass close to the Earth with a low enough velocity that one of these probes could reach them. Heck, some are easier to reach in that sense than the Moon! Any asteroid-directed probe can be equipped with sensors to make detailed observations, including composition. It could even be designed to land on the asteroid and return samples back to Earth, or leave when the observations are complete and head off to observe more asteroids up close and personal.

 


Step 2

Once a suitable asteroid is found, the idea is not to mine it right away for precious metals to return to Earth, Lewicki told me, but instead to tap it for volatiles — materials with low boiling points such as water, oxygen, nitrogen, and so on, which also happen to be critical supplies for use in space.

The idea behind this is to gather these materials up and create in situ space supply depots. Water is very heavy and incompressible, so it’s very difficult to launch from Earth into space (Lewicki quoted a current price of roughly $20,000 per liter to get water into space). But water should be abundant on some asteroids, locked up in minerals or even as ice, and in theory it shouldn’t be difficult to collect it and create a depot. Future astronauts can then use these supplies to enable longer stays in space — the depots could be put in Earthbound trajectories for astronauts, or could be placed in strategic orbits for future crewed missions to asteroids. Lewicki didn’t say specifically, but these supplies could be sold to NASA — Planetary Resources would make quite a bit money while saving NASA quite a bit. Win-win.

The details of exactly how they’ll collect these resources and store them may be revealed in the press conference Tuesday. If I can, I’ll ask.

 


Step 3

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CATEGORIZED UNDER: Astronomy, Cool stuff, NASA, Space, Top Post

Snapshots from Space

By Phil Plait | March 16, 2012 1:14 pm

My pal Emily Lakdawalla from The Planetary Society has started making a series of short videos about astronomy and space science. She’s made one about NASA images, seasons on Mars, and now this one on asteroid impacts:

And she’s wearing an SMBC shirt!

These are pretty good: short, informative, and I’d bet useful in the classroom as well. Emily writes The Planetary Society blog, too, so you should make sure that’s in your RSS feed. And subscribe to their YouTube channel, too!


Related Posts:

- Rosetta’s stunning Mars
- What happened to Phobos-Grunt?
- Women as planetary science role models
- Asteroid comparison chart, Part II

CATEGORIZED UNDER: Astronomy, Cool stuff, Space

TED talks now on Netflix… including mine

By Phil Plait | March 15, 2012 1:54 pm

I just got a press release that the folks behind the TED conference have partnered with Netflix, and many of the TED talks will now be available through the online video server. That’s pretty cool!

Even cooler: my own TED talk, "How to Defend Earth from Asteroids" is one of their initial offerings! They packaged a few space talks, including mine, along with talks by Brian Cox, Carolyn Porco (that one is a must-see), Jill Tarter, and many others. There are also packages about health, biology, computers, and more.

If you are a Netflix subscriber these talks are free. I’ll note they’re all online at the TED site as well, but this may open up the talks to a bigger audience, which I think is just fine. I have Netflix, and found them easily by searching on "TED" (duh).

Not only that, but TED has a new initiative for education called TED-Ed: Lessons Worth Sharing. These are short, great educational lessons that fit well inside established classroom curricula. There are lots of such things available, of course, but these are hand-picked and will augment a teacher’s lessons. I think this is a cool idea, since TED already has a trusted brand and a wide audience. Just to be clear, there lessons are online, not on Netflix like the big talks.

If you don’t have Netflix, well, like I said you can find these talks on the TED website. And because why not, here’s mine. Enjoy:

[You may need to refresh the page to get the video to load.]


Related Posts:

- My asteroid impact talk is now on TED!
- TED x ME
- Asteroid 2011 AG5: a football-stadium-sized rock to watch carefully
- Repeat after me: Apophis is not a danger!

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