| Early on the morning of June 30, 1908, a | | | | the naked eye. If the object was indeed a |
| tremendous explosion rocked the Tunguska | | | | comet, it must have approached from a |
| region of Central Siberia. Hundreds of square | | | | direction with a very small angular distance |
| miles of forest were completely flattened, a | | | | from the sun, rendering it invisible. Given |
| huge fireball rose into the sky, and a large | | | | an early morning time of impact, the comet |
| black cloud appeared above the region. A | | | | would then have approached from the east with |
| shock wave circled the globe twice, and | | | | the tail streaming ahead of the nucleus (away |
| strange, glowing skies ere evident throughout | | | | from the sun) towards the west which may |
| Europe and Asia for days after the event. | | | | account for the glowing night skies seen over |
| | | | Europe and Western Asia after the explosion. |
| Since the event occurred, several theories | | | | |
| relating to its origin have been presented. | | | | The proponents of the extraterrestrial |
| Some feel that the explosion was the result | | | | spacecraft theory dispute the comet theory |
| of a meteor impact, while others feel that a | | | | for several reasons. First of all, several |
| comet was responsible for the devastation. | | | | eyewitnesses claim to have seen the object |
| Still others feel that because of the | | | | approaching from the southwest, veer towards |
| observed trajectory of the incoming object, | | | | the east, then back toward the west before |
| it may have been an extraterrestrial | | | | exploding. Also, the object appeared to slow |
| spacecraft of some type. | | | | down just prior to the blast. The blast |
| | | | pattern itself appeared to be irregular, |
| Years later, when the first research team | | | | suggesting that the explosion occurred inside |
| finally reached ground zero, they observed no | | | | some type of restrictive shell. Other |
| crater, and could not locate any meteor | | | | evidence suggests the possibility that the |
| debris, so the meteor theory was dismissed | | | | blast was nuclear in nature, thus accounting |
| (by most), and the comet theory became | | | | for the increase radioactivity levels |
| popular. A comet, composed mostly of ice and | | | | reported in the region and accelerated plant |
| dust, would explode upon entering the earth's | | | | growth in the years following the explosion. |
| atmosphere, creating an airburst similar to | | | | |
| that observed in this case. The conversion of | | | | At best, proof of the source of the Tunguska |
| the kinetic energy of the incoming comet to | | | | explosion is far from definitive. |
| heat would result in a blast of tremendous | | | | Unfortunately, the region is not easily |
| proportions. | | | | accessible, and is not a pleasant environment |
| | | | to work in, so it is unlikely that we will |
| The question is: Why wasn't the comet seen as | | | | ever know for sure what precisely happened. |
| it approached the earth? A comet that close | | | | Expeditions are planned to probe some of the |
| to the sun exhibits a glowing nucleus and | | | | lakes and bogs near ground zero for meteoric |
| extensive tail, making it easily visible to | | | | evidence, but for now, speculation continues. |