Earth Rocks / Moon Rocks

[fahrquad]

My wife and I went to the Yucatan for our wedding anniversary (14th maybe?).  As far as she knows, we went to lounge on the beach at Puerto Morelos, but my ulterior motive was to go dive the cenotes (about a 75 minute drive).  The airport locator code for Cancun is CUN.  Pick up a car at your agency of choice and hit highway 180D west for 120 miles (197 km) for 2 hours and 17 minutes.  It took us over 3 hours, but the road construction apparently has been completed.  See, Trump made Mexico pay for something!!!

 

  https://www.google.com/maps/dir/Canc%C3%BAn,+Quintana+Roo,+Mexico/Chich%C3%A9n+Itz%C3%A1,+Yucat%C3%A1n,+Mexico/@20.9084104,-88.2701365,9z/data=!3m1!4b1!4m14!4m13!1m5!1m1!1s0x8f4c2b05aef653db:0xce32b73c625fcd8a!2m2!1d-86.8515279!2d21.161908!1m5!1m1!1s0x8f5138c6e391c0e7:0x7c1ea0a168994d9a!2m2!1d-88.5677826!2d20.6842849!3e0

[fahrquad]

There is POSSIBLE evidence for periodic mass extinctions from meteorites. https://medium.com/starts-with-a-bang/are-mass-extinctions-periodic-and-are-we-due-for-one-8185755207bd

"

 In a timeframe of just ~500 million years, you can only fit three possible 140 million year mass extinctions in there, and only about 8 possible 62 million year events. What we see doesn’t fit with an event happening every 140 million or every 62 million years, but rather if we see an event in the past, there’s an increased chance of having another event either 62 or 140 million years in the past or future. But, as you can clearly see, there’s no evidence for a 26–30 million year periodicity in these extinctions.

"

  

 

There are a lot fewer big objects still whizzing around the solar system these days compared to 65-120 million years ago.  Of course we could get hit by a big object at any time but the odds are a little lower.  I think the last big impact in the solar system was comet Schumacher-Levy hitting Jupiter in 1994.

 

https://youtu.be/HXgq3Iq4wOk?t=33

 

[fahrquad]

Earth impact graphics start round 4:24 in video above.

[fahrquad]

I would think that some of the debris blasted into space by Chicxulub impact is still falling to earth (or being burned up on re-entry).  While the Chicxulub impactor was a rocky body, the Tunguska impactor appears to have been an icy body, supposedly a comet or comet fragment.  I won't go into any more detail, but here is the link if anyone is interested in reading up on it.

 

https://en.wikipedia.org/wiki/Tunguska_event

[fahrquad]

I would think that some of the debris blasted into space by Chicxulub impact is still falling to earth (or being burned up on re-entry).  While the Chicxulub impactor was a rocky body, the Tunguska impactor appears to have been an icy body, supposedly a comet or comet fragment.  I won't go into any more detail, but here is the link if anyone is interested in reading up on it.

 

https://en.wikipedia.org/wiki/Tunguska_event

 

Alright, alright, I will add that the Tunguska impact is assumed to have been a comet since there is no clearly defined impact crater.  An alternate theory is that an asteroid fragment exploded in mid-air, also leaving no clearly defined crater.

[hazelm]

Alright, alright, I will add that the Tunguska impact is assumed to have been a comet since there is no clearly defined impact crater.  An alternate theory is that an asteroid fragment exploded in mid-air, also leaving no clearly defined crater.

Meaning when it got close to Earth, it was nothing more than gas.  Yes?  What in the gas created the "fireball" (if I may call it that)?  It was certainly a massive ending - if it ended.  Maybe it sailed on to the next planet?

[hazelm]

The Tunguska event is not fully understand, some tiny fragments of what MIGHT be bits of meteorite have been recovered. The wiki link here covers the basics, but 1000's of papers have been written with all sorts of speculations. https://en.wikipedia.org/wiki/Tunguska_event The eye witness accounts at the end of the link are interesting.

And folklore grows exponentially on the unknowns. 

[fahrquad]

Admittedly the Tunguska area is very remote, but word did reach civilization eventually.  A pretty decent photo for 1908.

 

[fahrquad]

One hundred years later.

 

[fahrquad]

Not the same vantage point or angle.

[hazelm]

I don't know what page  I ended up on but the picture of that fire burst looks very much like a firenado.    A firenado twists on itself like that as it burns.

 

I still ask, though:  Why would the asteroid burst in the air?  I thought asteroids were solid debris - rock, etc.  There must have been gas in it.  Or on the ground and it having flammable properties. 

[hazelm]

All right.  I confess I didn't read the entire article.  Did anyone ever tell reporters and writers in general that "all good things come in small packages?