Crater From 1908 Tunguska Blast Found

MaineCoasts writes "A team of scientists from the Marine Science Institute in Bologna claims to have found the crater left by the aerial blast of a comet or asteroid in 1908 in the Tunguska region of Siberia. The blast flattened 770 square miles (2,000 square kilometers) of forest, but to date no remains or crater have been found. This has left open the question of what kind of object made the impact. The team believes that, contrary to previous studies, nearby Lake Cheko is only one century old and 'If the body was an asteroid, a surviving fragment may be buried beneath the lake. If it was a comet, its chemical signature should be found in the deepest layers of sediments.' The team's findings are based on a 1999 expedition to Tunguska and appeared in the August issue of the journal Terra Nova."

Comments

I've always wondered

[Dunbal]

I remember reading about this as a kid, probably introduced to it by Carl Sagan in his "Cosmos" series.

At the time I wondered, after seeing all those flattened trees, how they failed to find the crater. Wouldn't it just be a case of going to several spots, drawing a parallel line to the flattened trees, then looking on a map for the point where the lines intersect? Presumably all the trees fell "away" from the blast area.

Re:I've always wondered

[eldavojohn]

At the time I wondered, after seeing all those flattened trees, how they failed to find the crater. Wouldn't it just be a case of going to several spots, drawing a parallel line to the flattened trees, then looking on a map for the point where the lines intersect? Presumably all the trees fell "away" from the blast area. No, the explosion was above ground level, see our prior discussion on this.

Also, my post on this has a link to a PDF with a sketch of the breaking apart and trajectories.

Also, remember how long ago this happened. There was an expedition there but they didn't have the technology we did. I'm not sure if the tree patterns would help you 100 years later.

Re:I've always wondered

[FredDC]

In theory yes, but you have to know that this is a very remote and large area. And they didn't have the technology we have available now.

Right now we'd simply take some pictures with a satelite, and fly some helicopters to the impact spot. Back then they would've had to mount an expedition on foot. And that was simply not feasible.

By the time it became possible to reach the impact site relatively easy, nature had already taken its course and finding the impact spot became impossible/very hard.

Re:I've always wondered

[larpon]

This picture was taken over the crater in Siberia with an onboard polaroid during the
Apollo 11 mission...

   \ | /
  -  O  -
   / | \

It reminds me of something...

Re:I've always wondered

[iamlucky13]

Also, remember how long ago this happened. There was an expedition there but they didn't have the technology we did. I'm not sure if the tree patterns would help you 100 years later.

Yes. Something that is easy for us to forget is that they didn't have roads, or even much in the way of all terrain vehicles, much less helicopters or satellites when this occurred. Not to mention, it was largely ignored until after the revolution and WWI were both finished up with. The first aerial photographs taken of the site were taken 30 years later and still clearly showed the fall pattern, but no crater was visible.

It's easy to look at the pictures and think you can simply follow the trees all the way to the center. Way easier said than done. First of all, the site is pretty much in the middle of nowhere. There's just a few scattered villages, no doubt with abysmal roads between each and almost nothing traversable with wheels leading anywhere else. They would have walked or ridden pack animals for the entire survey.

It's also a huge area. 80 million trees were felled over 830 square miles. Hunters (I've done my share) and loggers are probably familiar with trying to walk through such an area. The trees may look all neatly arrayed in a photograph, as if you could step easily from one to the next or walk between them like a trail, but the truth is far different. Without the perspective benefit from being atop a hill, the fall pattern is more difficult to discern. The branches will lie tangled, blocking the path at frequent intervals. The trunks will be random distances apart, some managing to overlap nearby trunks. They often sit several feet above the ground, making it easy to fall and twist an ankle or knee, and exhausting to climb over again and again and again. Vegetation will have sprouted up in the 19 years between the fall and Kulik's arrival, leaving a tangled mess of shrubs and briers that sometimes appear deceptively solid from above and forboding from ground level. A mile per hour is a decent speed walking through such an area with several days worth of supplies on your back.

But Kulik actually did push through to the center, and he found several trees standing upright, stripped of their branches, consistent with an airburst from above. He also found a bog he was convinced was a crater, but when he drained it there were old tree stumps at the bottom. For an impact to have formed the bog the blast would have shattered the old trees and tossed the remains out of the muddy crater.

Re:I'm a bit worried

[MarkGriz]

"If scientists can't find a crater that's 2,000 square miles across then what chance do they have the day they lose their keys down the back of the sofa?"

Considering YOU think that square miles are a measure of distance rather than area, and that kilometers are equivalent to miles, I'd say they have a better chance than you do.

Googlink

[PhilHibbs]

Google map of the point that the National Geographic map link goes to

Uni. Bologna homepage on Tunguska

[Paul Jakma]

Uni of Bologna have a site on Tunguska, including a whole section on this new, possible crater - with pictures.