Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. Eps. 621 & 622: Morning Sky & Lonely Vigil

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • David Rankin discovered undiscovered football stadium-sized Aten asteroid 2020 VZ5.
  • Hannes Groeller discovered 1,000’ diameter 2020 WP1 traveling through Ursa Major.

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.

Today’s sponsor:  Big thanks to our Patreon supporters this month: Rob Leeson, David Bowes, Brett Duane, Benett Bolek, Mary Ann, Frank Frankovic, Michael Freedman, Kim Hay, Steven Emert, Frank Tippin, Rani Bush, Jako Danar, Joseph J. Biernat, Nik Whitehead, Michael W, Cherry Wood, Steve Nerlich, Steven Kluth, James K Wood, Katrina Ince, Phyllis Foster, Don Swartwout, Barbara Geier, Steven Jansen, Donald Immerwahr

Please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at

Or please visit our Patreon page:


621: Morning Sky

Although the orbit of an Aten asteroid crosses our path in space on its travel about the Sun it stays mostly inside the Earth’s orbit making it difficult to discover.  Recently my Catalina Sky Survey teammate David Rankin spotted an undiscovered Aten asteroid in the hour before morning twilight, streaking through the constellation of Leo, while asteroid hunting with our 60 inch telescope on Mt. Lemmon, AZ.  

The Minor Planet Center used David’s discovery observations along with follow up data from telescopes in Arizona, Germany, and Pennsylvania to estimate the new objects size, path about the Sun, and give it the name 2020 VZ5.  This football stadium sized space rock travels about the Sun once every 306 days on a path which crosses ours twice a year once ahead of the Earth and the other behind us as we both travel about the Sun.  On its current path, occasionally 2020 VZ5 comes to about 13 times the Moon’s distance from us.  

According to the Purdue University and Imperial College of London’s impact calculator, an asteroid the size of 2020 VZ5 enters our atmosphere once every 240,000 years,  strikes the ground in broken pieces at a speed of 5 miles/second, and creates a crater 1.24 mi in diameter and 1400 feet deep in sedimentary rock.  Since it is likely to eventually collide with Earth, Venus, or our Moon asteroid hunters will continue to observe 2020 VZ5 to make sure its path does not change to become a threat to our home planet. 

622: Lonely Vigil

The Catalina Sky Survey Schmidt telescope on Mt. Bigelow, Az covers the entire sky once every three nights.  On some of these nights the telescope searches for Earth approaching objects near the ecliptic plane where the planets and most of the asteroids are located.  During these busy times the telescope takes images of many interesting moving objects.  On other long lonely nights the search takes the telescope to the far north portion of the sky where it is rare to spot any moving objects traveling through fields of millions of unblinking stars. On one of these vigils my Catalina Sky Survey teammate Hannes Groeller spotted an unusual bright fast moving object traveling through Ursae Major.  

For the 35 hours after Hannes posted his observations his discovery was tracked by telescopes at 20 different observatories around the world.  The Minor Planet Center used these observations to estimate the space rock to be 1000 feet in diameter, calculate the details of its 857.5 day long orbit about the Sun, and give it the name 2020 WP1.  The fact that its path is inclined by 39 degrees relative to the ecliptic plane containing the planets and most of asteroids suggests that it is the result of a violent collision long ago.  Such collision fragments tend to be made of strong materials such as iron and nickel making them of interest to future asteroid miners.  Since a giant space rock like this one impacts the Earth once every 840,000 years or so asteroid hunters will continue to track 2020 WP1 to make sure it does not become a threat to humanity.

End of podcast:

365 Days of Astronomy

The 365 Days of Astronomy Podcast is produced by Planetary Science Institute. Audio post-production by Richard Drumm. Bandwidth donated by and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. 

This show is made possible thanks to the generous donations of people like you! Please consider supporting to our show on and get access to bonus content. 

After 10 years, the 365 Days of Astronomy podcast is entering its second decade of sharing important milestone in space exploration and astronomy discoveries. Join us and share your story. Until tomorrow! Goodbye!