Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 191E & 192E: Big Rock & Birthday Asteroid

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s two stroy:

  • Alex Gibbs discovered 1 mile diameter 2015 VL142.
  • Rose Matheny discovered basketball court-sized 2015 VP105.

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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191E: Big Rock

Asteroid hunters find many of their objects traveling in the same plane as the planets.  Recently my Catalina Sky Survey teammate Alex Gibbs pointed the telescope away from the usual search area because weather conditions prevented him from observing in our regular spots. In doing so he found the 5th largest of the 1,357 Earth approaching objects discovered during the first 11 months of 2015.

Typically the near Earth objects asteroid hunters discover range from 10 feet to more than a mile in diameter.  Most Earth approaching asteroids are small with more than 2/3 of them being less than a few hundred feet in diameter.  Ones larger than about 10 football fields in size are rare and account for less than 1% of those found in recent years.    Alex’s large asteroid, named 2015 VL142, is nearly a mile in diameter.  Fortunately this asteroid never comes close since the impact of one of this size is capable of causing global climate change.  2015 VL142’s path around the Sun takes it from nearly out to the orbit of Jupiter to almost touching the Earth’s path around the Sun.

According to analysis done by Dr. Alan Harris, an asteroid the size Alex discovered is likely to strike the Earth every million years or so releasing the energy of 100,000 million tons of TNT.  Statistics suggest that there are 50 to 100 large undiscovered Earth approaching objects out there. Asteroid hunters will continue to search the skies for them.

192E: Birthday Asteroid

My Catalina Sky Survey teammate Rose Matheny spent her birthday observing with a telescope on Mt. Bigelow, Arizona.  She wished for a comet. Instead the Universe gave her an asteroid. Early in her 11 hour long birthday night Rose posted her observations of an unknown moving point of light in the night sky on a public website at the Minor Planet Center.  Her new object was observed for the next 43 hours by telescopes in Arizona, Utah, New Mexico, Romania, France, Italy, Hungary, England, and Kansas.  It was given the name 2015 VP105.

When Rose first spotted her birthday asteroid it was a million miles from her and was traveling away at 11 miles per second.  2015 VP105 has a diameter which is approximately the length of a professional basketball court.  It came near to planet Earth 7 times from 1936 to 2010 without humans being aware of its existence.  In 2015 this space rock came near to both the Earth and Moon.  It is not likely to come this close to our planet again until some time past 2034 AD . 

There are likely to be a million asteroids the size of Rose’s Birthday asteroid,  2015 VP105.  One of its size probably enters the Earth’s atmosphere every hundred years or so exploding at about twice the height airliners fly dropping small pieces onto the ground.

To paraphrase the Rolling Stones, perhaps if the Universe doesn’t give you what you want it will give you what you need.

End of podcast:

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