Podcaster: Dr. Al Grauer
Title: Travelers in the Night Digest: Human Geological Epoch & A Haul
Organization: Travelers in The Night
Link : Travelers in the Night
Description: Today’s 2 topics:
- Eric Christianson discovered 2016 AM2, a PHA, a Potentially Hazardous Asteroid.
- NASA’s NEOWISE Infra-Red comet & asteroid hunter satellite can, in a way, see inside comets by looking at heat. Comets C2015 X8 & C2015 YG1 are 2 comets it has discovered and examined.
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:
220 – Human Geological Epoch
In the space of less than a human lifetime most of the people on Earth no longer are able to experience the wonders of the natural night sky.
If your are wondering how far the human race has gone in changing our planet, you should consider the work of researchers who are members of the Geological Society of London. This group of scientists have published a paper in the Journal GSA Today in which they present hard evidence that human activity has caused changes in erosion and sediment build up worldwide, produced changes in the the carbon cycle and the global temperature, precipitated profound changes in the plant and animal kingdoms, and has changed the acidity of the worlds oceans.
Dr Colin Waters of the British Geological Survey said: “Humans have long affected the environment, but recently there has been a rapid global spread of novel materials including aluminium, concrete and plastics, which are leaving their mark in sediments. Fossil-fuel combustion has dispersed fly ash particles worldwide, pretty well coincident with the peak distribution of the ‘bomb spike’ of radionuclides generated by atmospheric testing of nuclear weapons.”
Human activity is thus being written into rock and ice layers currently being produced on planet Earth and suggests that we are embarking on a new geological epoch which may be named the Anthropocene.
It is time for our race to change some of its ways or be prepared to face the consequences of a radically different planetary environment.
221- A Haul
My team, the Catalina Sky Survey, discovered a very diverse group of 566 Earth approaching objects in 2015. Fortunately none of them will strike the Earth anytime soon. The smallest has a diameter which is less than the height of an NBA basketball player while the largest is nearly a mile in diameter. Most of these space rocks are small. 424 have diameters which would allow them to fit between the goal posts of a NFL football field. None of the 119 large enough to cause serious damage to humans are on a collision course with planet Earth.
These 566 Earth Approaching asteroids orbit the Sun with periods from less than a year to three plus years in length. All of their orbits can bring them near to the path of planet Earth about the Sun. Sixty four of these space rocks can come closer to us than the Moon. One of them, 2015 AQ43 is about 30 feet in diameter and missed us by less than an Earth diameter in 2010 without being noticed. Three of them were relatively near misses in that they came less than the Earth’s circumference from us in 2015.
My team, the NASA Sponsored Catalina Sky Survey continues to be on the look out for space rocks 24 nights every month using two telescopes in the Catalina Mountains north of Tucson, Arizona. Our goal is to find any large objects at least 50 years before they get too close for comfort to planet Earth.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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