Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 159 & 160: Planet’s Airglow & Number 1602

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • Dr. Candace Gray earned a PhD from New Mexico State University for her work to observe and understand Venus’s mysterious green airglow
  • 2015 OC22, 1200 feet in diameter, was discovered by the Pan-STARRS group in Hawaii.

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, Ron Diehl, 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, Semyon Torfason, Michael W, Cherry Wood, Steve Nerlich, Steven Kluth, James K Wood, Katrina Ince, Phyllis Foster, Don Swartwout, Barbara Geier, Steven Jansen

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:


159E: Planet’s Airglow

At the few remaining natural night sky viewing locations on Earth the horizon has a faint glow in every direction.  Near the magnetic poles, this night glow appears to join with the relatively bright higher altitude aurora which covers larger portions of the sky and exhibits beautiful colors including green and red. Green light is the strongest component of the Earth’ airglow and comes from oxygen atoms which have become energized by our Sun. 

The planet Venus is similar to the Earth in many ways. It also also displays striking differences.   One of these is that Venus does not have an internally generated magnetic field but rather a weak one produced by the solar wind. Astronomers have long puzzled over this weak magnetic field and the unexpected occurrence of a faint sporadic green night glow on our sister planet.

Recently Dr. Candace Gray earned a PhD from New Mexico State University for her work to observe and understand Venus’s mysterious green airglow and suggesting this is likely a global aurora about non-magnetic planets that occurs only after solar storms.   By using observations from Apache Point Observatory and spacecraft orbiting Venus to fuel atmospheric model calculations she has been able to connect Venus’s enigmatic green line to mass burps from solar storms on our Sun.

Dr. Gray’s work helps to better understand our own planet by comparing it with one of our neighbors in space. 

160E: Number 1602

The one thousand six hundred and second potentially hazardous asteroid was discovered by the Pan-STARRS group in Hawaii. Followup observations were made by  telescopes in Hawaii, France, Australia, Italy, Germany, and Pennsylvania. The Minor Planet Center used these vital observations to calculate an orbit and gave it the name 2015 OC22.

2015 OC22 is about 1200 feet in diameter.  Fortunately, on its current path, it can’t come closer than about 10 times the Moon’s distance from us.  An asteroid this size probably strikes the Earth every 100,000 years or so making a crater 3 to 4 miles in diameter. This particular asteroid’s orbit crosses the paths of Mars, Earth, Venus, and Mercury. It takes a bit over 3 years to make a single trip around the Sun.  In the past, it has made close approaches to the Earth in 1963 and 2012 and Mercury in 1972.

In 2015 this potentially hazardous asteroid will pass near Mercury and come a distant one third of the Sun’s distance from us.  It will make close approaches to Mercury in 2024 and 2068 and the Earth in 2055 and 2095.  The asteroid hunting community will continue to monitor 2015 OC22’s orbit for any changes which might occur.  2015 OC22 will continue to move through the inner solar system until it collides with another celestial object in the far distant future.

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!