A quick note to folks in the Fort Collins, Colorado area: I’ll be giving my "Death from the Skies!" talk on Thursday, November 3 (tomorrow as I write this) at the Colorado State University campus there. The talk will be at the Lory Student Center East Ballroom at 7:00 p.m.

It’s open to the public [UPDATE: admission is FREE!], so if you’re in the area, come see me show how an asteroid impact can ruin your whole day!

In September 2011, I was honored to be on the speaker roster for TEDxBoulder, which is a local though independently-run version of the much-lauded TED talks. My talk was about saving the Earth from asteroid impacts, something I’ve spent a lot of time thinking and writing about.

The talk is online, and I’ve included it here:

The "We have a space program" line is from science fiction author Larry Niven, so I can’t take credit for it, though I modified it to add the "we can vote" bit. Also, this was the biggest audience I’ve ever spoken to, and it was a great crowd. I was almost last on the roster, but the audience was attentive and clearly enjoying themselves. It was a really fun, energizing, and mind-expanding evening.

The other talks that night are being put online as well. If you ever get a chance to attend a local TEDx conference, you should.

Some new research just released asks a question near and dear to me: are there thousands of spinning white dwarfs in our galaxy, just waiting to explode as they gradually slow their rotation?

The answer is very probably yes. Let me be clear, as I always must be when covering topics like this: we’re not in any real danger from these things. Space is vast, and supernovae are few. If these things were that volatile we wouldn’t be here to talk about them in the first place.

But it’s still a very cool scientific question, and actually a fairly simple concept. Here’s how it works.

Imagine a binary system of two stars like the Sun, orbiting each other. One star nears the end of its life, swells up into a red giant, and blows off its outer layers. After a few millions years, all that’s left is its core: a dense, hot ball called a white dwarf. The size of the Earth but with the mass of a star, white dwarfs are pretty weird. They have incredibly strong gravity, which wants to crush them down even further, but they are supported by the electric repulsion of electrons, which is a pretty mighty force. It’s an uneasy truce.

It’s made even uneasier by the other star. It too eventually swells up, and can start to dump matter onto the dwarf (like in the picture above). If enough mass piles up, the immense gravity of the dwarf can induce nuclear fusion. Sometimes the material explodes, flaring in brightness, and we get a nova. Other times, if enough matter piles up — making the total mass of the white dwarf a bit more than 1.4 times that of the Sun — the ignition of fusion can cause a runaway reaction in the star, disrupting it entirely. The white dwarf tears itself apart, and you get one of the biggest and most violent explosions in the Universe: a supernova.

But there’s a hitch. (more…)

Blowing up a planet is hard. Really, really, really, really hard. In fact, if you had one "really" in that sentence for every Joule of energy it would take to make the Earth all explodey, you’d need more than 2 x 10³² of them. That’s a lot of "really"s.

I actually calculated that number using some basic physics and math, and then decided to write an entire article around it, which is now up on Blastr. It doesn’t matter how big a supervillain you are, blowing up a planet is next to impossible, despite the non-existence of Ceti Alpha 6.

There are ways of tearing a planet apart, actually, but I didn’t want the article to go on too long, and I figure exploding one versus ripping it apart are different things. Maybe I’ll do a follow up article. And really, why blow it up at all? If you want to kill everything on it, just set up a massive ad campaign for hair spray, sell the inhabitants a billion cans of the stuff, and then sit back and wait for them to destroy their ozone layer. Done and done.

[P.S. Today marks the 12th anniversary, ironically, of the Moon being blasted out of Earth orbit. Happy Breakaway day!]

- Blastr: My Favorite TV Scientists
- Blastroid
- Blastr: Other than that, Spock, how was the movie?
- Blastr: I Was A Zombie For Science
- Big budget movies that got their science right
- Master of Blastr

I’m very pleased to announce that I’ll be giving a presentation at TEDxBoulder on September 24 this year. TEDx events are independently organized from TED, but feature the same sorts of talks: inspiring, entertaining, and designed to help make the world a better place.

My topic? Trying to make the world a better place by preventing an asteroid impact from making it a far, far worse place. The other talks look pretty interesting, including one from Kimbal Musk, Elon Musk’s brother, and also from Jake Nickell, co-founder of the Threadless t-shirt company. I think this will be a very cool evening.

Tickets are on sale now but I hear it’s filling up quickly, so if you’re in the Boulder area and want to attend, better hurry!

SXSW (or South by Southwest if you want to make it easier to say out loud) is a major geekapalooza held every year in Austin, Texas. There’s music, film, and lots and lots of tech nerdery. I’ve wanted to go for a long time.

Now’s my chance, but I need your help! I was contacted by Stephanie Smith at JPL who is proposing a panel called "2012: You Bet Your Asteroid the World Won’t End", featuring JPL’s Veronica MacGregor, near-Earth asteroid expert, Don Yeomans, and me. The panel would be about end-of-the-world scenarios, something about which I have plenty of fun things to say.

The thing is, the panels have to be voted on, and that’s where you come in. All you have to do is go to the SXSW panel picker, register (that only takes a sec), and then you can vote for what is undoubtedly the best panel out of the 3285 listed.

If you do, I will love you forever and send you a unicorn^*. But please hurry — voting closes at noon Central (US) time on Friday, September 2. Thanks!

^* Offer void where unicorns exist.

A few days ago, the web was abuzz with something that looked like a very large meteor burning up over Peru. Here’s video from ITN news:

You can find similar videos on Youtube. However, is it actually a meteor?

Cutting to the chase, I don’t think so. I don’t have a lot of solid evidence either way, but all signs point that way. Here are my thoughts:

1) Meteors tend to move more quickly. They usually burn up around 100 km (60 miles) up, roughly, and are moving at a minimum of 11 km/sec (7 miles/sec) — Earth’s gravity pulls them in to at least this speed. If you’ve ever seen a meteor you know they zip across the sky in at most a few seconds.

2) The two trains (the technical term for what most people would call the tail or trail) are very odd — you can see them in the frame grab here. I’ve never seen a meteoroid (the actual solid bit moving through our atmosphere) produce more than one train. I don’t think this is an optical effect due to the camera but actually two distinct trains.

(more…)