Podcaster: Dr. Al Grauer


Title: Travelers in the Night 541 & 542: Most Dangerous in 2018 & Toughest Asteroid

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  •  Alex Gibbs found 3,400 foot diameter 2018 XV5, the largest potentially hazardous asteroid discovered in 2018.
  • Alex Gibbs discovered 1,200 foot diameter 2018 GG5.

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: David Bowes, Dustin A Ruoff, Brett Duane, Kim Hay, Nik Whitehead, Timo Sievänen, Michael Freedman, Paul Fischer, Rani Bush, Karl Bewley, Joko Danar, Steven Emert, Frank Tippin, Steven Jansen, Barbara Geier, Don Swartwout, James K. Wood, Katrina Ince, Michael Lewinger, Phyllis Simon Foster, Nicolo DePierro, Tim Smith, Frank Frankovic, Steve Nerlich

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:


541-Most Dangerous in 2018

My Catalina Sky Survey teammate Alex Gibbs found 2018 XV5, the largest potentially hazardous asteroid discovered in 2018  while observing with our 60 inch telescope on Mt. Lemmon, Arizona.  At an estimated diameter of 3,400 feet Alex’s discovery is one of the nearly 1,000, known,  1 KM or larger in diameter asteroids whose impact would produce real problems for humanity.  

According to the Purdue University and Imperial College of London’s Impact calculator an asteroid the size of 2018 XV5 enters the Earth’s atmosphere once every 240,000 years or so  releasing the energy of 1,260 megatons of TNT.  If you were 50 miles from the point of such an impact you would experience a 229 mph wind and the effects of a Richter Scale 7.3 magnitude Earthquake.  

Glass windows would shatter, multistory buildings would collapse, and up to 90% of the trees around you would be blown down with those left standing being stripped of leaves and branches.  The impact of a large space rock like 2018 XV5 would create a 5.7 mile diameter, 1890 foot deep crater in sedimentary rock.   Fortunately, on its current path, Alex’s 3,400 foot whopper cannot come closer than 12.5 times the Moon’s distance to humanity.  Not to worry.  Asteroid Hunters have not found a single space rock on a collision path with planet Earth.  

542-Toughest Asteroid

My Catalina Sky Survey teammate Alex Gibbs was observing in the constellation of Crater with our Schmidt telescope on Mt. Bigelow, Arizona when he discovered  2018 GG5.  This amazing asteroid is about 1,200 feet in diameter and orbits the Sun once every 1023 days on a path that takes it from out to between Mars and Jupiter back to only about 28% of Mercury’s  distance from our Star.  If you had thumbed a ride on 2018 GG5 on July 16, 2018, as it crossed the Earth’s orbit heading away from the Sun you would have been quite a ride.  

In early November of 2019 this quarter mile diameter asteroid will have reached its furthest point from the Sun some 359 million miles from our Star.  From this point on the relentless pull of the Sun’s gravity begins 2018 GG5 on its next death defying journey.  In late February of 2021 it will have crossed the Earth’s orbit heading for our star and on March 31 of 2019, 2018 GG5 will be closest to the Sun and be traveling at 78 miles per second.  At this scorching distance it will receive 12.6 times the radiation that heats the planet Mercury’s surface to 800 F.   This hardy space rock has made this trip many times and is likely to be made of extremely tough materials and in the future could prove to be a valuable source of raw materials for human space colonists.

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

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!