August Night Sky

The month of August has a plethora of astronomy to occupy your summer evenings. And at great risk of going apocalyptic on my readers it also brings something that should keep you up at nights.

Something worth worrying about.

For thousands of years the meteor shower that we call the Perseids is a consequence of earth passing through the debris field left behind by Comet 109P/Swift-Tuttle.  

Yup.  the periodic return of Swift-Tuttle bears the seeds of our own demise.

Swift-Tuttle is big (16 miles across) and fast (36 miles per second).  It is estimated that it is up to 300 times more powerful than the asteroid that struck earth and wiped-out the dinosaurs.  And sometime in the next couple of thousand years it is going to pass perilously close to our planet. 

Swift-Tuttle's next approach to earth will be in August of 2126 bringing it within about 14 million miles or 60 times the distance from the earth to the moon.  Current models predict that the comet won't get any closer than 80,000 miles of earth's orbit.  That may seem like a great distance but in outer space terms that is a near miss.  Under the worst of circumstances our gravitation field could alter the comet's trajectory causing it to strike the earth.

That would result in the largest mass extermination event in hundreds of millions of years.  Yowza.  Game over.  A terrible, horrible, very bad day.

Nevertheless, I certainly don't plan on being around over a hundred years from now much less 2400 years from now.

For the present we can sleep well...