Giant fireball in the sky was the first indication that an unknown celestial object had exploded over Siberia. In this artist's conception, Semen Semenov, who witnessed the blast at a distant trading post, starts to feel the heat.
Image: James Porto
In Brief
- Exactly 100 years ago a comet or an asteroid exploded a few kilometers above the Tunguska region of central Siberia, leaving a huge zone of destruction.
- Despite many searches, no one has found any remnant of the impact body. Such evidence could help scientists gauge the danger posed today by medium-size comets or asteroids.
- A team of Italian scientists has found evidence of a possible impact crater about 10 kilometers from ground zero. They will soon return to recover what may be a fragment of the cosmic object.
More In This Article
-
Photo Album
Slide Show: What Happened at Tunguska
Editor's Note: This story was originally printed in the June 2008 issue of Scientific American.
June 30, 1908, 7:14 a.m., central Siberia—Semen Semenov, a local farmer, saw “the sky split in two. Fire appeared high and wide over the forest.... From ... where the fire was, came strong heat.... Then the sky shut closed, and a strong thump sounded, and I was thrown a few yards.... After that such noise came, as if . . . cannons were firing, the earth shook ...”
Subscribe
Buy This Issue
Already a Digital subscriber? Sign-in Now
If your institution has site license access, enter here.
Already a Digital subscriber? Sign-in Now
If your institution has site license access, enter here.
See what we're tweeting about
12 Comments
Add Commenta further deep study is requierd for different impact cretors on earth surface ( iand & ocean floor) to assess the size of impact earth ecology,
Reply | Report Abuse | Link to thisearth rotation, an earthquek frequency variation. i hope the gulf Mexico ,
victoria lake(Africa), black sea is result of such big impact.
rcdohare25@yahoo.co.in
a further deep study is requierd for different impact cretors on earth surface ( iand & ocean floor) to assess the size of impact earth ecology, earth rotation, an earthquek frequency variation. i hope the gulf Mexico , victoria lake(Africa), black sea is result of such big impact. rcdohare25@yahoo.co.in
Reply | Report Abuse | Link to thiscool
Reply | Report Abuse | Link to thisWe had a Tunguska Event centennial commemoration party in honor of the event. Here's a picture of the cake that our hostess (not me!) baked, featuring blown-over pretzel trees and a mystery lake burbling with the eldritch horror of diet coke & mentos:
Reply | Report Abuse | Link to thishttp://flickr.com/photos/bmljenny/2644526861/
perhaps the event was caused by the comet entering the atmosphere being made of frozen methane or even water, heated by the entry into the atmosphere to a point of instantaneous sublimination in the oxygen rich lower atmosphere where it exploded causing the masssive blast, but leving no crater or fragments, with the early glow being combustion in the less oxygen rich higher statosphere..
Reply | Report Abuse | Link to thisGentlemen,
Reply | Report Abuse | Link to thisI believe you overworked your secretary when he/she transcribed the Lake Cheko coordinates on page 83. According to Google, the correct longitude is 101 degrees, not 100 as stated.
The BMC
too many pages
Reply | Report Abuse | Link to thisThere may be a crater.
Reply | Report Abuse | Link to thishttp://tech-notes.info/2007/06/30/rr-crater-may-resolve-1908-tunguska-mystery-my-take-the-aliens-did-it/
http://www.livescience.com/space/scienceastronomy/070626_st_tunguska_crater.html
Perhaps there's another explanation. It could have been a space ship that was in deep trouble that exploded. It can't be ruled out except for complete skeptics and dummy's.
Reply | Report Abuse | Link to this"It could have been a space ship that was in deep trouble that exploded."
Reply | Report Abuse | Link to thisEverything is possible, but there are no evidence for this or anything like this. Actually this seems highly improbable and highly implausible.
Some people think also, that Tesla aimed a pulse at the place where he thought that it would benefit a Polar traveler.
Reply | Report Abuse | Link to thisMaybe he miscalculated and it went it bit off the target.
Since it is one application of the E-Bomb, it cannot be ruled out.
Has anyone carefully investigated the possibility of a tremendous crater called Michigan, including the surrounding lakes? Of course, the Great Lakes were formed by the melting at the end of the ice age, but there had to be a reason the water chose this location, instead of somewhere else. The reason, perhaps, being that the general formation was already there - a classic circle of low ground, with a raised center.
Reply | Report Abuse | Link to thisTake a look at the Michigan Bedrock Geology at a site like
http://www.ncrs.fs.fed.us/gla/geology/mi-bedrock.htm.
The shape is sure right for a crater. Note that this bedrock would generally have been deposited after the impact.
Something caused the continent to nearly split apart about 1.2 billion years ago. One end of the rift is in the lower Peninsula of Michigan, and it curves around through Lake Superior and then southerly. If an impact had anything to do with it, a few million years of lava that followed would have wiped out a lot of the evidence, as did the later scraping of mile-high ice, and a lot of sedimentation.
I have read that the rift is thought to have been caused by an upwelling from the mantle. However, it was unusual because there was not the normal lift in ground surface preceding the rift. If the upwelling resulted from a sudden impact, that might explain that.
I am not a geologist, but merely a person who was struck by the visual similarity of the bedrock map to a weathered crater image.
Of course, an equally interesting finding would be if one or more of the Great Lakes started as a somewhat smaller impact site.