History Teaches - June 30

[azmouse]

June 30, 1908: The Tunguska Event

"Understanding the laws of nature does not mean that we are immune to their operations." ~ David Gerrold

The Tunguska event was a powerful explosion that occurred near the Tunguska River in Russia on June 30, 1908. The explosion knocked over an estimated 80 million trees covering 830 sq miles and struck people unconscious some 40 miles away.

An asteroid entered Earth's atmosphere traveling at an estimated speed of about 33,500 miles per hour. The enormous space rock heated the air around it to 44,500 degrees Fahrenheit. At a height of about 28,000 feet, the combination of pressure and heat caused the asteroid to break apart, producing a fireball and releasing energy equivalent to about 185 Hiroshima bombs.

Although the meteor burst in the air rather than hitting Earth, this event is still referred to as an impact. It is estimated that the shock wave from the blast would have measured 5.0 on the Richter scale.

Because of the remote location and political upheaval in Russia, no expedition was mounted to investigate the site for 20 years.

The possibility that a major metropolitan area could be destroyed by a similar meteor explosion has helped to spark discussion of ways to deflect asteroids and comets heading toward Earth.

So what's the difference between an asteroid, a meteor, and a meteorite? Good question.

Asteroids are space objects made up of rock and metal, and are classified as near-Earth objects. An asteroid ignites as it enters the Earth's atmosphere, creating a visible streak of light called a meteor. If the object doesn't vaporize completely and crashes into the Earth, it's called a meteorite.

[jaxx]

Good grief, that is unbelievable. No wonder people get worried when these things pass close to the earth.

[azmouse]

(06-30-2011 12:56 PM)jaxx Wrote:  Good grief, that is unbelievable. No wonder people get worried when these things pass close to the earth.

This is amazing and just happened on June 27: http://www.thetechherald.com/article.php...se-tonight

...expect to witness the illuminated passage of ‘2011 MD’ as it zips by at a distance of between 8,000 and 11,000 miles—that’s closer than some global positioning satellites.

Likely to come as something of a surprise to those given to watching the skies based solely on the astronomical calendar, the meteor in question was only discovered last Wednesday by an automated telescope in New Mexico.

An initial alert was then transferred to the International Astronomical Union’s Minor Planet Center in Massachusetts, after which scientists began tracking the space rock and deemed its trajectory to be safe.

Although 2011 MD is thought to measure only 45 metres across, which is fairly small where meteors are concerned, it could still cause massive amounts of damage if it were to impact the planet’s surface.

[nofurylike]

(06-30-2011 02:19 PM)azmouse Wrote:  This is amazing and just happened on June 27: http://www.thetechherald.com/article.php...se-tonight

...expect to witness the illuminated passage of ‘2011 MD’ as it zips by at a distance of between 8,000 and 11,000 miles—that’s closer than some global positioning satellites.

Likely to come as something of a surprise to those given to watching the skies based solely on the astronomical calendar, the meteor in question was only discovered last Wednesday by an automated telescope in New Mexico.

An initial alert was then transferred to the International Astronomical Union’s Minor Planet Center in Massachusetts, after which scientists began tracking the space rock and deemed its trajectory to be safe.

Although 2011 MD is thought to measure only 45 metres across, which is fairly small where meteors are concerned, it could still cause massive amounts of damage if it were to impact the planet’s surface.

that part adds some of the scary. i kind of get to thinking that with all that super space equipment they have, they would see something like that before it was already here.
but noooooooo.
eek

thanks, again, azmouse!

[nofurylike]

fascinating, but kind of

thank you for posting that, azmouse!!