Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps.  135E & 136E: High Traffic Area & Radio Eyes

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • Francesco Manca of the Sormano Astronomical Observatory is doing some of the important work of keeping track of the asteroids which can make close approaches…
  • Invisible to us, are the radio waves occupying a vast region of other wavelengths.

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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135E: High Traffic Area

Francesco Manca of the Sormano Astronomical Observatory is doing some of the important work of keeping track of the asteroids which can make close approaches to our Earth, our Moon, and other objects in space.  He has compiled the fact that the asteroid hunting community has found more than 2000 small asteroids, of less than several football fields in diameter, which can make close approaches to us.  Nearly 700 have orbits which allow them to come closer to the Earth than our Moon.  So far more than 250 of these small asteroids have come or are predicted to come less a lunar distance from our home planet. 

A recent one of these very close approaching objects was discovered by my NASA funded, Catalina Sky Survey teammate Carson Fuls.  It is about 35 feet in diameter. Not long ago it passed about 4 Earth diameters from the Earth’s surface. During this time it was observed by telescopes in Arizona and Chile.  It orbits the Sun every 3.3 years and will come near the Earth again in 2099, 2106, and 2113.  About every 100 years or so it comes close enough to the massive planet Jupiter to have its motion effected by it.

Another somewhat larger asteroid was discovered when it was far away and faint by astronomers using a 4 meter telescope in Chile. It may come near to us and our Moon in a few months.  We will not know much about the details of its close approach until it gets brighter and the asteroid hunting community is able to obtain more observations to pin down its path in space.

136E: Radio Eyes

Human eyes are sensitive to wavelengths or colors in a small portion of the electromagnetic spectrum.  

If you woke up tomorrow morning with radio eyes your surroundings would look very different. Invisible to us, are the radio waves occupying a vast region of other wavelengths.These invisible radio waves are produced by a number of very interesting physical processes in the Universe. In fact how things look would depend on the part of the radio spectrum that you could see.

The Sun is the brightest object at most radio wavelengths.  To your radio eyes, the rest of the sky would contain many surprises.  

The Moon and planets do not shine by reflected radio waves from the Sun but glow because of their thermal radiation making them look quite different to your radio eyes.

Your radio eyes would not detect most of the bright stars familiar to us even though they are part of our Milky Way galaxy and are located within a few hundred light years of planet Earth. 

Instead the “bright stars” seen by your radio eyes would be quasars which are emitting radiation from the vicinity of super massive black holes at the centers of galaxies.  Amazingly enough the radio bright quasars are located, on average,  5 billion light years from us. 

One your radio eyes strangest sights would be the glow that you would see in every direction.  It is the Cosmic Microwave Background radiation from the Big Bang. It is the strongest component of all electromagnetic radiation, fills the Universe,  and marks the beginning of the Universe as we know it. 

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

End of podcast:

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