DEATH BY ASTEROID CRASH?

A week ago I posted on Death by a Gamma Ray Burst?  This week, I focus on another space invader, a large asteroid.  PBS has had several documentaries on this topic:  The Asteroid and the Dinosaur and  Dinosaur Apocalypse.

The scientific term for the above is Impact Event.  The biggest Earth event might have been the Big Splash, or the Theia Impact:

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  This when our Moon was formed approximately 4.5 billion years ago.
• Theia, the mythical Greek Titan, was the colliding body, mother of Selene, the goddess of the Moon.
• The isotope ratios of lunar and terrestrial rock are identical.
• There are many theories, but one is that the Moon was formed by the tangential impact upon Earth of a body the size of Mars.
• Much of this giant-impact consensus emerged from a 1969 conference held at Kona, Hawaii.  Those who don't believe are called the agnostics.

But our solar system is today quite different, and planet-sized impact neighbors are no longer present.

• 2 billion years ago an asteroid called Vredefort, from 12.4 to 15.5 miles across, struck South Africa, leaving a crater of 100 miles diameter.  There was not much life on Earth then to cause any extinction problem.  Time has eroded the crater, but this is something from NASA.

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  Then that most famous of all impacts, the Chicxlub meteor, 6 to 9 miles across, hit the region near Mexican's Yucatan Peninsula, creating a crater of 112 miles diameter, killing off the dinosaurs.  It is estimated that the energy released was 50,000 times more than the magnitude 9.1 earthquake that his Sumatra in 2004.  Again, there is no impact evidence.  Much of this remains speculation.

Of course, there are smaller craters, such as the Ries Crater, where the town of Nordlingen is now within the inner ring in Germany.  The full impact crater has been eroded over the past 15 million years.  

The Pingualuit Crater, Quebec, Canada, is 2.1 miles in diameter.

Formed just 50,000 years ago in northern Arizona is the Barrington (Meteor) Crater, with a diameter of 0.8 miles.

There are 190 confirmed craters on Earth.  Note that Moon craters remain largely untouched by nature, and the estimate there is 30,000 of them.

Devastating asteroids rarely crash on Earth.  A major impact within the past 100,000 years is the Yilan Crater of 1.45 mile diameter found in Northeast China's Heilongjiang Province.  Crashed around 50,000 years ago, so possibly was witnessed by humans.

Researchers are discovering around 500 sizable space rocks over 460 feet across in our solar system neighborhood each year.  NASA last year successfully tested the first attempt to intentionally move an asteroid, the one to the left.

Plus the technology is not here to be 100% sure, so the B612 Foundation formed two decades ago to keep us safe from asteroids.  Ten years ago, one of the founders, Ed Lu, a former astronaut, gave a talk on the University of Hawaii Manoa Campus, and I had a chance to discuss with him how their fundraiser was developing.  While Project Blue Revolution is seeking $150 million to build and operate the Pacific International Ocean Station, B612 has a goal of $450 million.  They apparently failed, and are pursuing other options.  Blue Revolutionists Leighton Chong and Benny Ron with Lu.

So should you be worried about menacing asteroids?  Well, there appears to be no known threat for the next century, and the likelihood of a major impact in the next thousand years is exceedingly low.  But if you die via asteroid, this is how it will happen.  You can read that article.

What about a third space invader.  A more intelligent civilization with malice in mind?  Science fiction is filled with them, and the success of numerous films indicate that there is fear.  Frankly, I'm not worried, and will explain why in an upcoming posting.

Hurricane Idalia reached Category 4 strength, then slightly weakened to a Category 3 at 125 MPH, making landfall in Florida's Big Bend near Keaton Beach just before 8AM, almost exactly as predicted by the integrated computer model.  Idalia will remain at Category 1 hurricane strength through most of her movement over Florida.  While the eye will miss the population centers, there will be considerable damage from winds and floods.

The still dangerous Typhoon Saola in the West Pacific was a super typhoon, but is now down to 150 MPH and still headed for Hong Kong.  However, Saola's track will amazingly turn left away from this city, weaken, and head back east almost in parallel to the current line.  Never seen this type of activity in the Orient, with all those circular movements.

Also in the West Pacific is Tropical Storm Haikui, who today weakened to 50 MPH, then strengthened to 60 MPH, and will reach hurricane strength tomorrow.  The eye will head north of Zhejiang and should make landfall as a Category 1 hurricane on Sunday.

Just thought I'd show another ocean cyclonic storm heading for Hawaii, being thankful that it never attained hurricane strength, and should further weaken into a remnant low, bringing some rain.  Now only at 40 MPH, Post-Tropical Cyclone Irwin seems headed on a path to take him north of the Hawaiian Islands.

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