Podcaster: Dr. Al Grauer
Travelers in the Night Digest: 297 & 298:White Sky & Rosetta

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • Light pollution not only costs us huge amounts of money, but it deprives everybody of the wonders of the night sky. The IDA can help. See
  • The ESA’s Rosetta spacecraft visited Comet 67P and found 16 types of organic molecules during the 2 years it was at the comet.

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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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297 – White Sky
It is likely that millions of children will never have the opportunity to see the Milky Way or a meteor streaking across the night sky unless they experience a massive failure of the electrical distribution grid. No one hopes for such an event since it would have many potentially tragic consequences.

Humans have arrived at the situation where at night 80% of the world’s population live under a white sky by a combination of thoughtlessness and a relatively cheap energy supply. The result is a massive waste of resources and money. In addition glare produced by poorly designed lighting causes accidents and does not deter crime.

Fortunately the International Dark Sky Association continues to advocate ways in which we can save money and protect the beauty of the natural night sky. Further, this organization , nicknamed the IDA, identifies and seeks to protect the remaining places on planet Earth where you can still experience and be inspired by the beauty of the Universe which surrounds you. The inventory of International Dark Sky Places on the website will help you to locate a place where you can experience the mysteries of the natural night sky.

From the time your ancestors left Africa 50,000 years ago until relatively recently every human was able to look into the night sky and wonder what is out there. Take a star chart, a flashlight with a red filter wrap attached by a rubber band, and visit a place where you can see what you have been missing. Learn the names of some of the bright stars which you will then recognize each year when they appear as the Earth Travels about the Sun.

298 – Rosetta
The Rosetta Spacecraft left planet Earth in 2004. During its twelve year lifetime this robotic emissary traveled 5 billion miles on 6 trips around the Sun, flew by Earth three times, visited Mars, and cruised by two asteroids. Rosetta needed to take such a long path to use the gravity of Earth and Mars to accelerate it to a speed which would allow it to rendezvous with a comet. Upon arrival, Rosetta successfully spent two years studying the comet at close range and sent a probe to it’s surface. It’s life ended when its human masters put it on a collision course with Comet 67P’s nucleus.

Before the Rosetta space mission humans had no idea of what a comet nucleus looked like or the fact that a comet nucleus is a tiny world with its own set of geological processes which shape it.

Astronomers have long theorized that comets brought water and organic materials to a dry sterile Earth billions of years ago. Rosetta’s lander found water, molecular oxygen, and nitrogen streaming from pours in the comet’s nucleus.

The 16 different types of organic molecules which Rosetta measured included amino acid glycine which is an important component of DNA and cell membranes. The water Rosetta found has left us with additional questions since the isotopes of hydrogen it contains are in different proportions to what is in the water on Earth. This means that comets like 67P could not have brought water to Earth and we will need to look elsewhere for the source of our world’s unique oceans.

Even though the Rosetta spacecraft no longer transmits data its legacy will continue for decades to come.

End of podcast:

365 Days of Astronomy
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