Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 583 & 584: A Woman & Pluto & Pop Up Comets

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  •   Elizabeth Williams graduated from MIT in 1903, and used the motions of Uranus and Neptune to predict the location of Pluto.
  • David Rankin was asteroid hunting in the constellation of Virgo when he spotted C/2020 B3 Rankin.

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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583: A Woman & Pluto

In 1781, while looking through a telescope he made himself, William Hershel discovered the planet Uranus. Using Uranus’ motion relative to the distant stars, French astronomer Urbain Jean Joseph Le Verier predicted the existence of the planet Neptune solely using calculations based on Kepler’s laws of planetary motion and Newton’s law of gravity. In a triumph of reality based science, when astronomers pointed their telescopes to the position Le Verier had calculated there indeed was the planet Neptune.

In the early 1900’s Astronomer Percival Lowell theorized the unusual motions of Neptune indicated a 9th planet at the outer reaches of our solar system. Lowell’s search for the mysterious Planet X was continued by Clyde Tombaugh who in 1930 discovered Pluto. Behind the scenes, Lowell and Tombaugh observations were guided by calculations made by a mathematician named Elizabeth Williams. William’s graduated from MIT in 1903 as one of the top students in physics and mathematics. In addition to being able to perform complex mathematical calculations by hand Williams wrote in cursive with her right hand and printed with her left.

As the head “human computer” at Lowell Observatory Elizabeth Williams used the motions of Uranus and Neptune to predict the location of Planet X.  Elizabeth Williams died penniless at the age of 102 years. In 2020 a graduate student at Lowell Observatory, Catherine A. Clark, is finally giving Elizabeth Williams some of the recognition she deserves.

584: Pop Up Comets

My Catalina Sky Survey teammate David Rankin was asteroid hunting in the constellation of Virgo when he spotted a fuzzy ball with a tail moving through the night sky. For 10 days, after David posted his observations on the Minor Planet Center’s Near Object Confirmation Page this new comet was tracked  by observers at a dozen observatories around the world and was given the name C/2020 B3 Rankin.  Since human observations only cover a tiny fraction of Comet Rankin’s trajectory, we can only estimate that on its current path this frozen stranger travels from somewhere between the orbits of Mars and Jupiter out to more  than 30 times the distance of Pluto from the Sun and back again once every 50,000 years or so. When Comet Rankin last visited our neighborhood Neanderthals and our other ancestors were living in the stone age.  When Comet Rankin returns 50,000 years from now it is hard to predict if our race will have survived climate change, virus pandemics, and other events hard to imagine.  

Astronomers have come to realize, that although Comet Rankin is unlikely to become a bright comet, that there are likely to be a many such frozen objects with nuclei larger than 1 Km in diameter that can come closer than the planet Mars.  The small possibility that such frozen gas ball could come near Earth at a speed of more than 30 miles per second producing a bright naked eye comet gives us a sense of wonder as to what else could literally pop up out of nowhere .  

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

End of podcast:

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