[Update: It looks like the cause of this was a gas bottle exploding, and not a meteorite. See the update for 21:15 UT below).]

A deadly explosion and fire occurred in Argentina overnight, reportedly killing one woman and injuring several others. Two homes, a store, and several vehicles were destroyed or damaged.

The thing is, while it’s not clear what caused this incident, several people said they saw a ball of fire descend from the sky when it happened.

Neighbors’ accounts describe a ball of fire coming from the sky as the cause of the explosion. The chief of the firefighters, Guillermo Pérez, however, said the "causes remain unknown" and that "gas containers were found intact," ruling out a gas related incident.

Other reports are similar; in that article the ball of fire was described as being blue. I know a lot of folks will think this was caused by a meteor, but it’s a bit early to run with that yet. For one thing, it could’ve been a small plane on fire, for example; this happened very early in the morning (2:00 a.m.), and from the reports I’m seeing it’s not clear if the witnesses were already awake when they saw this or were awakened by it. Eye witness reports are notoriously unreliable, and it can’t help if the witnesses were suddenly woken up.

[Update (17:30 UT): This is looking less like a meteorite to me; this news story has a witness saying he saw the blue fire after hearing the explosion, and after he went outside to see what was what. Thanks to JoseManuelp2 for the link.]

As testament to that, I’m seeing some reports that the ball was red, and a picture was posted to the imaging site yfrog claiming, without any any supporting evidence, to be a shot of it. I include it here; note it’s very dark, out of focus, and very low resolution (from the pixelation). I have no clue what this picture shows, but I have my doubts it’s a fireball. I expect we’ll be seeing lots of rumors and things like this today.

[Update (21:15 UT): The image shown here of the red fireball is a hoax, and the man responsible for it has been arrested. Also reported in that link is that there were gas bottles secretly hooked up to a pizza making stove in a nearby house, and that this may be the cause of the explosion. I expect that is the final straw on this story -- enough evidence is piling up that this was not something form space, or even from the sky; it was some kind of terrestrial event, as expected.]

The explosions and devastation appear to be very real, though. This is the only video I could find on YouTube, and it has no audio, but it shows the aftermath:

I don’t see any obvious airplane wreckage, but it’s hard for me to see that a meteorite impact would’ve done this; for it to have been big enough to cause this much devastation, there would’ve been a big crater as well (like the one that hit in Peru a couple of years back). None is evident, so I’m strongly of the opinion something more terrestrial was to blame here.

I won’t be surprised to hear people asking if this was from the UARS satellite, too. However, that’s pretty much impossible; the satellite came down Friday night, and there couldn’t have been pieces of it still in orbit two days later. Also, again, the type of destruction seen here is unlikely to have been from just a simple impact.

Hopefully we’ll find out soon. If you hear anything please leave a comment below (with a link if you have one), and I’ll post an update when I learn more.

[Update: A grass fire in Texas Saturday night has been reported, and it's claimed to be linked to something falling from the sky. Again, a meteorite is extremely unlikely there, since it would take a big impact to ignite fires. Stuff like this happens all the time, and remember Texas is extremely dry right now. I would guess this was fireworks, but there's not much info on this story either. Thanks to Baron Grim on Twitter for the story.]

Tip o’ the Whipple Shield to Antropomorficah on Twitter. Image credit: screen grab from embedded C5N video.

As I write this, storm clouds are gathering in the west. That’s a pretty common situation here in Boulder, Colorado, in the summer. We get fine, clear mornings, and sometimes rain in the afternoon. In general big storms aren’t exactly rare, but this summer we’ve been getting pounded. On my bike rides it’s been routine to see the creeks in the area swollen to the point of overflowing.

But this summer, that situation has turned more dangerous. We’ve been getting some serious flood scares, and the reason may not be obvious to people who don’t live in the area: fires.

Last year, the Fourmile Canyon area north and west of Boulder burned pretty vigorously for many days. The smoke plume was visible from space, and it caused a lot of local grief. What wasn’t clear to me at the time was how this would affect flooding.

The image above, taken on June 7, 2011, is from NASA’s Earth Observing-1 satellite, and is a combination of far-infrared and visible light. Water (reservoirs and lakes) shows up as purple in this false-color image, vegetation is mostly green, and red/orange shows the fire damage. You can see Boulder to the lower right of the burned area.

When fire burns off all the plants, there’s nothing to hold the rain water in when we get storms. The water all washes downhill, in this case into the Fourmile Creek. That runs into the Boulder Creek, and that, well, here’s a natural color image which shows why that’s bad:

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I’ve posted quite a few pictures from NASA’s Earth-observing Terra satellite over the past few months, some of them showing devastating natural disasters. But I never thought I’d post one that shows something so close to home.

This image was taken yesterday, September 6th, at about noon Mountain time:

That shows the plume of smoke from the Fourmile Canyon fire that I wrote about yesterday. The image is roughly 300 km (190 miles) across. The vertical dividing line is the actual edge of the Rocky Mountains; to the left (west) are the mountains, and to the right (east) is the start of the Great Plains stretching most of the way across the US.

The green smudge just to the south of the plume is Denver, and the smoke goes directly over Boulder… and my house. The fire is still going as I write this, but the winds have shifted and there is no longer a plume overhead. It smells like ash outside though, and the foothills — usually visible a few kilometers to the west from my house — are almost totally hidden.

I appreciate all the notes and tweets I’ve gotten, but we’re safe here. The fire is pretty far west of us, though we could see it poking over the first set of foothills last night. Creepy.

My brother-in-law has taken some amazing pictures of the fire from his house, located even farther to the east than where I am. This one shows the tops of the fires.

I’ll add that the sunset yesterday was desperately beautiful:

The smoke is made up of tiny particles of soot and ash. When blue light hits them, it scatters like a pinball off a bumper. So when you look to the Sun through the smoke, all the blue light has bounced off in a different direction, leaving only the redder light able to make its way straight to your eye. This happens on a lesser scale every night with particles in the air, making sunsets red. But this fire has really strengthened the effect, and the Sun went through myriad shades of red on its way down past the mountains last night. It was astonishing. Making it even more wrenching was knowing what was a causing it, and that there were people in the middle of all that smoke trying to put the fires out.

So far, there are still no reported injuries, though many homes have been destroyed and over 1000 people have been evacuated from the area.

My thanks to NASA_GoddardPix for the link to the Terra picture.

When I posted the awesome video of a fire tornado last week, I had only heard rumors of such things. Apparently, they’re more common than I thought.

Here’s another amazing video, and this one is even better: it’s longer, and you can see the rotating smoke cloud around the column of fire!

This really is a fantastic demonstration of how microscale weather works. Imagine: a fire starts. As the air is heated above the fire, it rises, and the upward motion can be very strong. This leaves a lower pressure spot at the fire, and the air from outside the fire rushes in to fill the gap. The air is very turbulent, and as the inward-moving air from one side hits air coming in from the other, swirls can form. These get amplified by the constant gale of air, and rotation on a larger scale can get started and sustained. The whirlwind gets pumped by the hot air rising, and the next thing you know you’ve got a full-blown tornado of fire.
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