Podcaster: Dr. Al Grauer


Title: Travelers in the Night 119E & 120E: Deafening Silence & Kowalski’s Forever Comet

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • More than 50 years of searching for signals from other civilizations in the Universe has produced a deafening silence.
  • Richard Kowalski has an instinct for discovering interesting objects. Like Comet C/2015 D5 (Kowalski).

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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119E: Deafening Silence

More than 50 years of searching for signals from other civilizations in the Universe has produced a deafening silence. There is no evidence that aliens have visited the Earth or exist anywhere.  There are many hints that life might exist in other places but there is no conclusive proof that it does.  

Some argue that life is exceeding rare and that we are likely to be the only advanced civilization in our Milky Way galaxy.  They site the fact that we haven’t discovered alien microbes, alien radio beacons, alien robotic spacecraft, alien markers on the moon  as indications that technological societies are not rampant in the Milky Way.  Professor Brian Cox of Manchester University goes even further and believes that the development of multi-cellular organisms and the extinction of the dinosaurs are so unique that intelligent life could not have happened twice in the Milky Way. 

The heavier elements like iron, sulfur, phosphorous, nitrogen, and carbon essential to life as we know it were forged in the interiors of the first few generations of stars in the Milky Way.   Further the frequency of life destroying gamma ray bursts was higher in the early universe than it is now.  These two facts make it more likely for life to develop in solar systems which have formed since about the time ours did.  

My money is on the concept that there are many planets which host living organisms.  Recent discoveries indicate that there may be as many as 40 billion habitable planets in the Milky way alone.  On some of them civilizations like are ours are likely to be emerging.  The physics of the Universe requires large allocations of energy and resources to become spacefaring.  Humans have so far dabbled in a few baby steps beyond our planet and made some attempts to listen for other beings.  What else is out there remains to be discovered.

120E: Kowalski’s Forever Comet

My Catalina Sky Survey teammate Richard Kowalski has an instinct for discovering interesting objects.Recently he spotted a fuzzy looking moving faint light in the night sky.  It was then observed by telescopes in Italy, New Mexico, and Texas and given the name C/2015 D5 (Kowalski). When Kowalski first spotted this comet it was traveling about 12 miles per second away from the Sun and was about 344 million miles from planet Earth.

About 14 months before Kowalski spotted it, Comet C/2015 D5 (Kowalski) was about 6 times brighter than it was on his discovery images.  It had gone un-noticed by human observers when it was closest to our planet at which point it was about two and a half times our distance from the Sun to us.  It could have been detected by a small backyard telescope and an electronic camera had anyone known where to look.    
We don’t know if this comet dropped out of the Oort cloud of small cold objects which orbit far from our Sun or if it traveled into our solar system from the vicinity of a distant star.  However, its speed, direction, and the laws of Physics enable humans to predict where it will go in the future.

Currently it continues to move away from our Sun.  In the fall of 2035 C/2015 D5 (Kowalski) will continue to move into interstellar space and be further out than Pluto’s average distance from the Sun.  At that point it will be traveling at a leisurely 6 miles per second in a direction between the constellations Libra and Scorpius. It is not heading towards any star in particular, however, if it was traveling at 6 miles/second in the direction of the nearest star it would take more than 130,000 years to get there. 

Comet C/2015 D5 (Kowalski) is likely to continue its cold lonely journey between stars till the end of time.

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

End of podcast:

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