Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps.  573 & 574: Sweet Asteroid & Record Year

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • A large, 4.6 billion year old, meteor exploded over Murchison, Australia on 28 September 1969.
  • In 2019, asteroid hunters set a new record by discovering 2,433 Earth approaching objects.

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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573: Sweet Asteroid

Early in the history of Earth surface conditions on our planet were too hot and dry to support the rich chemistry of life. However, further from our infant Sun, carbon rich organic molecules, which are the basis for all life as we to know it, began to form and were encapsulated in asteroids. Much of what we know about this era in our solar system came to us when a large, 4.6 billion year old, meteor exploded over Murchison, Australia on 28 September 1969 at about 10:58AM local time. Eye witnesses reported that a large fireball separated into three pieces producing a cloud of smoke. Thirty seconds later a loud booming sound was followed by a strong smell of methylated spirits. Some 200 lbs of fragments were recovered over a 5 square mile area.

Over the past 50 years, in the interior of these meteorites, scientists have discovered a large variety of extraterrestrial organic substances. These include amino acids, sugars, alcohols, and a variety of aromatic hydrocarbons. Other meteorites have been found to contain vitamin B3 and even sugars leading to speculation that meteor bombardments could have brought life’s ingredients to a sterile Earth. To further research this hypothesis, The NASA OSIRIS-REx Spacecraft operated by NASA/Goddard and the University of Arizona’s Lunar and Planetary Laboratory is on a sample and return mission to Asteroid Bennu.  Bennu is a carbonaceous asteroid thought to be similar to the parent body of the Murchison Meteorite and is likely to hold valuable secrets.

574: Record Year

In 2019, asteroid hunters set a new record by discovering 2,433 Earth approaching objects including 85 which could potentially become a threat to planet Earth. Fortunately, none of these 2,433 nearby celestial neighbors, having an average diameter of 300 feet, is on a collision course with humanity.  My team, the Catalina Sky Survey once again led the pack by discovering 1,067 of these space rocks.  

The thirty, very closest approaching space rocks, discovered in 2019, average 42 feet in diameter, and can come close enough to pass through the cloud of communication satellites which encircle our world.  A small space rock of this size enters our atmosphere once every 10 years or so producing a spectacular light show and rains a few pieces to the surface for meteorite hunters to discover.  Arguably, the 1200 foot diameter space rock, 2019 LZ1, is the most potentially dangerous asteroid identified in 2019.  It was discovered by my Catalina Sky Survey teammate Teddy Pruyne with our 60 inch telescope on Mt. Lemmon Arizona.  

An asteroid the size of 2019 LZ1 enters our atmosphere every 100,000 years or so and feels like a magnitude 7.2 earthquake 100 miles away.  On its current path 2019 LZ1 can come to less than 3/4 of the Moon’s distance from us.  Asteroid hunters will continue to track 2019 LZ1 to be sure its orbit doesn’t change to make it a threat as it passes near Mercury, Venus, Earth, and Mars.

For Travelers in the Night this is Dr. Al Grauer.

End of podcast:

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