Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 173E & 174E: So Many Possibilities & Breaks Happen

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • The number of possible places in a galaxy for life as we know it to develop…
  • A break in the monsoon weather pattern allowed Richard Kowalski to discover 2015 RT1, 2015 RC, 2015 RD and 2015 RS1.

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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173E: So Many Possibilities

The number of possible places in a galaxy for life as we know it to develop depends on the number of stars which have planets, the presence of necessary elements such as iron, oxygen, nitrogen, and carbon, and the freedom from nearby supernova which could sterilize an otherwise habitable planet.

In a large spiral galaxy like our Milky Way, the forces of chemistry and physics are likely to be creating a new star like our Sun approximately once a year.  Every one of these could very well have a number of planets orbiting it. The NASA Kepler spacecraft has discovered a tip of the iceberg list of Earth sized planets.  There are estimated to 11 billion planets likely to be orbiting Sun like stars in our home galaxy.  

If that is not enough, a recent survey of nearby galaxies has found that a giant elliptical galaxy could have 10,000 times more Earth like planets than our own spiral Milky Way galaxy.  In addition a giant elliptical galaxy is rich in the elements necessary for life and has 10 times fewer life killing supernova explosions than a spiral galaxy like our own.  

The good news, the Sloan Digital Sky Survey in New Mexico has reported the discovery more than 150,000 galaxies which are rich with the three life enabling properties. The bad news is we will get monologues and not dialogs since it will take 9 million years for radio waves from the closest one to reach us and another 9 million years for our answer to make the trip back.

174E: Breaks Happen

Hunting asteroids by poking around in clear holes between cloud layers can be very tiresome, however, sometimes it has its rewards.  A break in the monsoon weather pattern over southern Arizona allowed my Catalina Sky Survey Teammate, Richard Kowalski, to discover four new Earth approaching objects during the part of a night it was clear. 

One of Kowalski’s new discoveries, 2015 RT1, would fit on an olympic sized basketball court, orbits the Sun once every 342 days, and makes close approaches to Venus, Earth, and our Moon.  On its current path it occasionally comes to within about 3 lunar distances from us.  It is extremely unlikely to enter our atmosphere anytime soon.

Two of these new discoveries 2015 RC and 2015 RD can approach to within about 12 times the Moon’s distance and are no threat to planet Earth.

The largest of the four, 2015 RS1, is about the size of a 71 story building, orbits the Sun in a bit over 3 years, and came near Earth in 1909 and 2015.  It was observed 22 other observatories after Kowalski posted his discovery observations on a Minor Planet Center webpage. It’s orbit takes it on a path from near Earth halfway out to the planet Jupiter and back again.  2015 RS1 was initially classified as potentially hazardous one but that was changed when further observations indicate that this big boy’s approaches never will bring it closer than about 19.5 times the distance to the Moon from us. 

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

End of podcast:

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