Podcaster: Dr. Al Grauer
Title: Travelers in the Night Digest: Eps. 257 & 258: Raw Asteroid & Odds of Aliens
Organization: Travelers in The Night
Link : Travelers in the Night
Description: Today’s 2 topics:
- Dr. Karen J. Meech of the University of Hawaii has studied comet C/2014 S3 (Pan-STARRS) which appears to be a very old asteroid in a comet’s orbit in the Oort cloud. It’s one that hasn’t been “baked” by long exposure to the Sun.
- Dr. Adam Frank of the University of Rochester & Dr. Woodruff Sullivan of the University of Washington have published a paper ( https://arxiv.org/abs/1310.3851 ) addressing the odds of technologically capable alien life appearing in a given volume of space. They posit that it’s possible that we are the first such species in a cube 1,000 LY on a side.
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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Transcript:
257 – Raw Asteroid
Most asteroids that we observe have been baked by the Sun for billions of years. As a result, any ices or frozen gases that they may have once possessed are long gone. Comets on the other hand have spent so much time far from the Sun that they still contain volatile materials. As a typical comet approaches the Sun, the frozen gases and ices it contains evaporate to form a beautiful coma and a long tail.
Recently the Pan-STARRS group in Hawaii discovered a weakly active comet with a very short tail. Dr. Karen Meech of the University of Hawaii’s Institute of Astronomy headed up a team which analyzed the data obtained from observations by the European Southern Observatory Very Large Telescope in Chile and the Canadian-French-Hawaii telescope on Mauna Kea. Their results suggest that, this comet, C/2014 S3 (PANSTARRS) is a ancient rocky body which was formed about the same time as the Earth. A relatively short time after formation it was ejected from the inner solar system. It took up residence in the Oort cloud far from the Sun where it remained until fairly recently. Dr. Meech concludes “We already knew of many asteroids, but they have all been baked by billions of years near the Sun. This one is the first uncooked asteroid we could observe: it has been preserved in the best freezer there is.”
Astronomers will now be on the look out for other objects like this one to provide important insights into the origin and formation of our solar system.
258 – Odds Of Alien
Recently Dr. Adam Frank of the University of Rochester and Dr Woodruff Sullivan of the University of Washington published a paper in which they addressed the question “What are the odds that humans are the only technological species that has ever arisen in a given volume of space?
These researcher’s calculations indicate that we are likely to be the first advanced civilization in a cube 1000 light years on a side centered on our Sun. However, they show that even if the if the odds of a planet developing a technological society are as low as your chances of winning the power ball there are likely to be hundreds of civilizations in the Milky Way and millions of civilizations in the observable Universe. The Frank and Sullivan results thus strongly suggest we are not unique and alone in the Universe.
Humans are on their way to making permanent changes to our planet’s climate which may eventually spell the end to our current level of technology. Do typical civilizations that arise in the Milky Way only last a few centuries after achieving high tech mode? If that is true then those intelligent societies that have formed are already gone and no more will develop before the end of our civilization.
Humans continue to look into the night sky and wonder what is out there. The immense distances and the uncertain lifetime of an advanced civilization make it seem unlikely that we will discover intelligent beings outside of Earth. However, I remain hopeful of one day waking to the news that we have received signals from thinking beings which live elsewhere in the Milky Way.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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