Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 233E & 234E: Asteroid Awareness & Anatomy Of An Extinction Crater

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s two stroy:

  • You are less likely to be injured by a space rock than you might think. Recently in response to a question from a reader of the “Asteroid Day” blog, my Catalina Sky Survey team captain Eric Christensen, wrote a blog piece entitled “Is It Just Me, Or Are Asteroids More Dangerous They Used To Be?”.
  • By drilling into a crater rim, researchers hope to discover how the Earth and its life forms recovered from an asteroid impact.

Bio: Dr. Al Grauer is currently an observing member of the Catalina Sky Survey Team at the University of Arizona.  This group has discovered nearly half of the Earth approaching objects known to exist. He received a PhD in Physics in 1971 and has been an observational Astronomer for 43 years. He retired as a University Professor after 39 years of interacting with students. He has conducted research projects using telescopes in Arizona, Chile, Australia, Hawaii, Louisiana, and Georgia with funding from NSF and NASA.

He is noted as Co-discoverer of comet P/2010 TO20 Linear-Grauer, Discoverer of comet C/2009 U5 Grauer and has asteroid 18871 Grauer named for him.

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233E – Asteroid Awareness

Recently in response to a question from a reader of the “Asteroid Day” blog, my Catalina Sky Survey team captain Eric Christensen, wrote a blog piece entitled “Is It Just Me, Or Are Asteroids More Dangerous They Used To Be?”.

In it, Eric points out that astronomers are detecting many more of the asteroids that come near planet Earth than we did in the past. These discoveries result in many more news stores about asteroids currently being published than what we saw 10 years ago.

Eric also comments on the fact that news, both true and false, spreads rapidly from postings on the internet. For example, in the past few years he cites reports of asteroid impacts which were widely quoted even though the events in question were later discovered to have no relationship to asteroids at all. Unfortunately, these unsubstantiated rumors have influenced people’s impressions about the danger posed by objects from space.

Eric concludes his piece with a summary of the tiny but not zero probabilities that space rocks of various sizes will strike and do damage to members of the human race.

Bottom line is that Earth approaching asteroids are a part of our environment. Their tiny spectacular threat to us is not increasing. The vast majority of asteroid impactors are small and if you are lucky will treat you to a nice light show. In fact personally, you are more likely to be killed by an earthquake, flood, tornado, car crash, airplane disaster, or a gun than you are by being hit by an object from space.

234E – Anatomy of an Extinction Crater

About 66 million years ago a 6 mile diameter asteroid impacted the Earth. It landed off the coast of the Yucatan Peninsula in Mexico, creating a crater more than a hundred miles in diameter. This event has been widely accepted as creating a fire storm which was bad news for the Dinosaurs and the other species which went extinct at that time. On the other hand, this impact may have been good news for our mammal ancestors which were able to hide underground, emerge, and flourish in its aftermath.

In order to investigate the aftermath of the potentially dinosaur killing asteroid impact, researchers are drilling a mile deep core sample into the inner ring of the Chicxulub crater which the impact produced. Their drilling rig sits on legs which lifts it above the waves on the surface of the 56 feet of water covering their target. Once through the 1800 feet of limestone which has been deposited since the event, the crew will drill day and night extracting 10 foot cores as they go through the more than a half mile of material which is the geological record since impact. Laying the cores end to end allows the scientists to measure changes in rock layers, microfossils, and DNA as the Earth and its life forms recovered from the asteroid impact. The 300 foot layer immediately above the rocks forming the peak crater rim is likely to be made up of the ash and other debris which fell out of the atmosphere in the weeks after the impact. What story will it tell? Stay tuned.

End of podcast:

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