Podcaster: Dr. Al Grauer
Title: Travelers in the Night Digest: Eps.429 & 430: 2017’s Catch and Deportee
Organization: Travelers in The Night
Link : Travelers in the Night ; @Nmcanopus
Description: Today’s 2 topics:
- In 2017 my team the Catalina Sky Survey led the world in the discovery of Earth approaching objects by identifying 987 of them as they whizzed by us
- The beautiful star cluster the Pleiades in the constellation of Taurus is about 100 million years old making it one of the youngest objects that you can see in the natural night sky.
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:
429 – 2017’s Catch
In 2017 my team the Catalina Sky Survey led the world in the discovery of Earth approaching objects by identifying 987 of them as they whizzed by us. The largest is 2017 DO36 which is 3,250 feet in diameter while the smallest, 2017 UL6, is less than 5 feet in diameter. None of the 987 are likely to strike the Earth anytime soon although 17 of them can theoretically come closer to the Earth’s surface than the communication satellites. 45 of our 2017 asteroid discoveries are large enough and can theoretically come close enough for NASA to designate them as Potentially Hazardous so that asteroid hunters will keep close track of them as they pass near to other objects in space. Fortunately none of these potentially dangerous neighbors will impact the Earth for hundreds of years. Earth approaching asteroids range from loose collections of dust and rocks to solid metallic objects. 21 of our 2017 discoveries must be very tough rocky metallic objects since they regularly survive on paths which take them closer to the Sun than the planet Mercury. Some of the nearly 300, 10 to 70 foot diameter asteroids my team discovered in 2017 could contain hundreds of pounds of rare metals like gold and platinum. Unfortunately asteroid hunters do not have access to the large expensive telescopes required to measure the pattern of colors in the light each asteroid we discover reflects from the Sun. If we did we could provide you with a treasure map of which ones to mine.
430 – Deportee
The beautiful star cluster the Pleiades in the constellation of Tauris is about 100 million years old making it one of the youngest objects that you can see in the natural night sky. Looking a bit like a little dipper this prominent group of stars has been recognized in cultures as diverse as the Aboriginal Australians, Celts, Arabs, Chinese, Japanese, Aztec, Cherokee, Hindus, as well as those of the Bible. In 2017 astronomers discovered something about the Pleiades to ignite the imagination of modern humans.
Data obtained by observing Oumuamua (“Oh-moo-ah-moo-ah”), the first object humans have identified which is definitely from outside of our solar system suggests that it is an icy body with a red, rock appearing shell, of carbon rich organic material. By tracing Omuamua’s path for millions of years into the past, Dr. Fabo Feng of the University of Hertfordshire , found that it’s slow speed in the vicinity of 5 stars in the Pleiades suggests that it was ejected from one of them. Additional scientific research finds that close double stars are common in the Pleiades while another suggests that Oumuamua may be a fragment from a planet which was torn apart in a close binary star system. It is likely that in the next few years asteroid hunters will detect more objects traveling through our solar system giving scientists additional opportunities to measure their compositions and research their origins. In the meantime check out the Pleiades with your unaided eye, binoculars or a small telescope and contemplate the messengers it might be sending our way.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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