A photo of the Swift-Tuttle comet, taken when it passed by back in 1992 [Photo by Gerald Rhemann]
It's possible that the Swift-Tuttle comet, which brings the Perseid meteor showers, could someday crash into Earth and bring about doomsday.
If you look at the surfaces of planets like Earth, Mercury, Venus, and Mars, you'd see evidence that these planets have been the targets of comets and asteroids for a very long time. This, of course, hasn't really stopped. Particles from outer space keep falling into Earth, and they can be as small as grains of sand or bigger than mountains. Our planet has also already taken 139 known major hits. There may be more, as some impact craters have already been erased by erosion or other causes.
All objects in the solar system that flies past Neptune and closer to the sun soon becomes a comet. As the object comes near the sun, the ice on it begins to melt and creates the “tails” characteristic of the streaks we see in our sky. If the comet crosses the Earth's orbit, it creates a meteor shower that can be visible to us from the ground.
It's possible that the Swift-Tuttle comet will slam into the Earth at some point in the future [Image by James Thew/iStockphoto]
The Perseids create the most consistent meteor showers that visit our skies. The Swift-Tuttle comet crosses the Earth's orbit and brings about the shower of lights that we see in August of every year. It's quite the sight, the shower of meteors that the Swift-Tuttle comet brings. About 60 to 100 meteors streak through the skies per minute, which is quite amazing to behold.
However, scientists warn that we may have to enjoy the beauty of the Perseids while it lasts, because one day the meteors may be a sign of doomsday. It's possible that Jupiter will exert gravitational influence on the Swift-Tuttle comet, making it change course and head straight for Earth instead.
Just how bad can it be should this happen? Well, bad. When the comet enters the atmosphere, it will hit the ground at a hundred times the velocity of a bullet just a second later. Vaporized stone will shoot out of the impact site, gouging a hole in the atmosphere. The vaporized rock then cools and condenses back into tiny rocks, which then fall back down to the ground and heat up as they descend. The air grows hot as well, causing plants, trees, and buildings to catch fire.
The Perseids when they came in August 2009 [Photo by NASA]
More things can happen should a comet the size of Swift-Tuttle hit the Earth, but it's clear that it's a Very Bad Thing to happen. The comet's nucleus measures 26 kilometers across, so it has quite a considerable size. A body like that slamming into Earth at top speed can spell disaster for the planet.
However, the good news is that there's only a very small chance of this happening. The comet makes a complete orbit around the sun every 133 years, and will return in the aforementioned date. However, when the comet comes back in 2126, it'll be passing closer to Earth. Each time the comet comes around, its path veers closer and closer.
A nudge from Jupiter may change the course of Swift-Tuttle and send it straight for us. If that happens, it's doomsday indeed. It can trigger the biggest extinction event the world has seen in 100 million years.
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