I think it’s so utterly cool that this married couple discovered that the big rock decorating their garden was a meteorite that started its journey to Earth half a billion years ago.
I write this post full well knowing that meteorites commonly strike our planet: there have been 1,086 meteorite “falls” (witnessed impacts) and 38,660 meteorite “finds” in the history of our planet. I once had the privilege to view the Barringer Crater in Arizona, a crater extending .73 miles in diameter caused by a meteorite impact only 40,000 years ago.
I tend to think of the Earth as stable and the meteorites are striking us. The truth is that all of us are streaking through space on a huge rock we call Earth. It’s equally amazing that the solar system once did not exist and that it will one day cease to exist. We are privileged to be cognizant of this amazing tour of space, passengers who are lucky to be alive and lucky to be conscious of this experience, all of us touring on the skin of our planet. All of this constitutes the most amazing and true story ever, but I’ve never yet read any of this in any newspaper headline.
I've visited several known meteor craters, including the one near Winslow and the Roman-walled city of Tübingen, Germany. I've also visited several volcanoes and calderas. We live on a dynamic planet. But our knowledge is recent. I was born before we knew about plate tectonics. In just the last decade we've learned where continents came from (granite is lighter than basalt), and why the Ozark Mountains are uplifted (the Bermuda hot-spot).
As Erich points out, our planet sweeps its orbit clean (part of the new definition of "planet" that leaves out Pluto), but it is quite a dynamic structure even without that continual influx.
Here's a nice plot of impacts by frequency and size:
<img src="http://rst.gsfc.nasa.gov/Sect18/impact-frequency.jpg" width="425">
Click for Source page at NASA.gov
Dan: That's terrific graphing. So much information in such a compact space. Thanks.
An incredibly lucky video of a huge object crashing into Jupiter. http://blogs.discovermagazine.com/badastronomy/20…