By now you’ve probably heard of the extremely bright fireball over Utah last Wednesday, proving once again that really cool stuff happens when I’m on travel and can’t write about it. Worse, it was seen from Denver, which means I might’ve had a shot at seeing it myself.

Sigh.

Anyway, this meteor was so bright it overexposed security cameras, turned night into day, and cast obvious shadows on the ground. This video shows several different views of it:

Whoa.

The coolest thing about these videos is, to me, the way the shadows of objects move rapidly around as the meteor flashes across the sky. I describe this very thing in the opening vignette of the asteroid impact chapter of my book Death from the Skies! The video is pretty much exactly as I imagined it would be. Yikes.

Of course, not everyone thinks this was just a chunk of rock burning up harmlessly in our atmosphere. Because, after all, why assume it was a natural event that occurs quite often, when you can add layers of nonsense and conspiracy to it? Fark alerted me to the idea that this was actually a nuclear missile shot down over the US, despite the video, pictures, and eyewitness accounts completely contradicting the idea that this was anything other than a meteor. But for some people, facts won’t get in the way of a good story!

Anyway, while spectacular, the Earth is probably subjected to meteors like this several times a year. As I have said before, now that we have security cameras and phones with video, we’ll be seeing more and more of videos like this, which is a good thing: it’ll make people more aware of the sky. I’m all for that!

I’m sure I’ll get some doomcriers in the comments. If you really think the Mayan calendar says the world will end in 2012, then I strongly urge you to read Aveni’s book. He’s an actual Mayan scholar, he knows his stuff, and he’s not out to either scare you or reassure you: he’s out to tell the truth.

This series of images [as usual, click to embiggen], from the European Southern Observatory’s Very Large Telescope, will take some ’splainin. Hang on.

A supernova — an exploding star — is among the brightest single objects in the known Universe. A supernova can release as much energy in a single second as the Sun will in a thousand years.

Most people think of supernovae as massive stars exploding at the end of their lives, but there is another kind. When the Sun finally dies in a few billion more years, it will shed most of the material making up its outer layers, revealing the white-hot, dense core. This superhot ball will have half the mass of the Sun in it, but only be the size of the Earth. We call such a thing a white dwarf.

If a white dwarf orbits a normal star like the Sun, it can draw material off. This matter piles up on the surface and can eventually detonate like a stellar thermonuclear bomb. We call these Type Ia supernovae.

The thing is, massive stars are bright, so we can see them a long way off. We know of many stars in our galaxy that can blow that way (though all too far away to hurt us). But a Type Ia progenitor is faint, and hard to spot. Usually, the first notice we get of one is when it explodes, and we see the sudden and vast increase in light in a distant galaxy.

But astronomers have spotted a potential Type Ia supernova in our own galaxy, a ticking time bomb about 25,000 light years away. Called V445 Puppis, in November 2000 it underwent an explosive event: not a supernova, but a regular nova, the detonation of small (in cosmic terms) amount of material. Still, it ejected a lot of matter — several times the mass of the entire Earth — at very high speed, about 24 million kilometers per hour (14 million mph). That would reach from the Earth to the Moon in one minute flat. Over the course of several years, astronomers have taken images of the expanding debris, and the change — seen in the picture above — is dramatic, lovely, and terrifying.

The debris did not expand spherically because the two stars are in a tight orbit, circling each other rapidly. The matter drawn off the normal star forms a thick disk around the white dwarf. When the material on the surface exploded, it couldn’t go through the disk, so it went up and down, above and below the disk. Over time it forms what’s called a bipolar structure, because it comes out of the poles of the star. We see lots of similar bipolar objects, but not usually in a system that’s about to go bye-bye.

Tellingly, there is no detectable hydrogen in the system. The surface of the white dwarf appears to be mostly helium, and the normal star looks to be dumping only helium on the white dwarf. Type Ia supernovae are hydrogen poor, even lacking it completely, so that fits.

Also, the mass of the white dwarf in V445 Puppis is on the thin hairy edge of the maximum it can be before it blows. When a white dwarf reaches 1.4 times the mass of the Sun, it goes kablooie (I had to calculate this as a homework problem in grad school). V445’s mass? 1.35 times that of the Sun.

Yikes.

So when will the system go off? Hard to say. It may not be for thousands of years, or even longer. At that distance, it will be very bright in the sky, brighter than Venus. It won’t hurt us; it’s way too far away to to do that. But a nearby supernova of this type would be a huge boon to astronomy! It’s this flavor of supernova we use to measure the expansion of the Universe (since they are so bright they can be seen very far away, and tend to blow up with the same brightness every time).

It’s a little funny to think that the death of a star so many quadrillions of kilometers away can actually be a benefit to us. But remember, the calcium in our bones and iron in our blood came from supernovae like the one V445 Puppis will eventually become, so not only do we learn more about the Universe from them, we owe our very existence to them as well.

I visited RPI many years ago (it was on my list of potential colleges when I was in high school, but that’s a long story), and it’s gorgeous. This time of year it’ll be spectacular, I bet, so I’m really looking forward to this!

Then I am very pleased to let you know that a group of artists there have created an exhibit based on my book, Death from the Skies! The exhibit is hanging at the ABC No Rio site, and runs from now until November 25 (actually it started last week). The viewing times are Sundays 1:00 – 3:00pm and Wednesdays & Thursdays 4:00pm – 7:00pm.

This is very cool, and I am deeply honored they based their work on my book. I was contacted by artist Brian George about it some time ago. Just recently he sent me some snapshots, and I was totally blown away by this:

I recognized this poor sot right away, and if you’ve read the first few pages of the book you will too. He’s the first guy killed by the Universe, straight away in Chapter 1. But don’t fret too much about him: everyone dies in the book. Over and over again, even.

I love the shadows of the trees in that drawing. Read the book to find out why. <Mwuahahahaha!>

The artwork on display is eclectic and interesting, and if you’re into astronomy and mayhem you want to go! The artists include Michael Estabrook, Brian George, Jacob Hashimoto, HC Noel (who drew Mark, above), Kevin Pyle, Kelly Savage ("Galaxies" over there on the left), William Stamos, Es Muss Sein Quartet & B-Cat and C-Town.

There’s a Facebook group for the exhibit, too.

And as an aside, if you happen to be in NYC Friday November 6, why not pay my friend, the wonderful flame-haired chanteuse Marian Call, a visit at her east coast debut? Her voice and music are really good, and she sings about cool scifi stuff, and even has a song the title of which I suggested to her. She’s awesome.

Of course, if you’re not in NYC, but instead are in Florida, that’s OK, because then you can go to Carl Sagan Day on Saturday, November 7!

It’s in honor of Sagan’s birthday, which is on November 9th. He would’ve been 75 this year. Sagan inspired a generation of astronomers, and in reality a whole generation of people to look at the sky and appreciate the — yes, I’ll say it — cosmos.

Celebrating his life is a great idea, and the folks at BCCC have a full day planned (the schedule is online in PDF and Word formats). A lot of good speakers will be giving talks, including my friend Jeffrey Bennett (who wrote Max goes to the Moon series of kids’ books), skeptic and "Point of Inquiry" podcast host D. J. Grothe, and NASA astrobiologist and impact expert David Morrison (via satellite). I’ll be giving my Death from the Skies! talk at 4:00 (with David there, I’ll have to be on my toes). They’ll be showing "Cosmos" continuously in one room, with kids’ activities in another. There’s a planetarium show in the evening, too.

And this will be very special: James Randi will be there, talking about Sagan. The two were friends. Randi has a lot of personal insight on the man and will have wonderful things to say. This is a don’t-miss opportunity, folks. I think I’m looking forward to that part most of all.

For more info, there’s contact info on the Carl Sagan Day website. Also, there’s a writeup in the Broward/Palm Beach New Times.

This really will be a fun and wonderful tribute to Sagan. I’m very pleased and honored to be a part of this great day for a great man.