Podcaster: Dr. Al Grauer
Title: Travelers in the Night Digest:Eps. 395 & 396: House Sized Space Rocks & Jupiter
Organization: Travelers in The Night
Link : Travelers in the Night ; @Nmcanopus
Description: Today’s 2 topics:
- Throughout history small close approaching space rocks have been a part of our environment. Now, thanks to improved telescopes and cameras, asteroid hunters are routinely discovering these small asteroids as they pass closer than the Moon is to us.
- Meteors, shooting stars, or falling stars are different names for the streaks of light in the night sky which are in reality the dying embers of tiny asteroids. These small interplanetary travelers were speeding along at between 7 and 44 miles per second when they entered the Earth’s atmosphere.
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:
395 – House Sized Space Rocks
Throughout history small close approaching space rocks have been a part of our environment. Now, thanks to improved telescopes and cameras, asteroid hunters are routinely discovering these small asteroids as they pass closer than the Moon is to us. Since these tiny asteroids are only bright enough to detect for a few days out of their long, many month duration paths about the Sun, astronomers have had difficulty in determining how many of these small space rocks may exist in near Earth space. This effort received more emphasis when a house sized space rock exploded over Chelyabinsk, Russia in 2013 releasing about 10 times the energy of the Hiroshima atomic bomb. Although this asteroid was tiny compared to the one that ended the dinosaurs rule of the planet, the air blast the Chelyabinsk bolide produced caused nearly 1,500 human injuries and damaged more than 7,000 buildings.
In a 2017 paper in the Astronomical Journal, Dr. David Trilling of Northern Arizona University and his group of researchers present data from the Blanco 4 meter telescope at the Cerro Tololo Inter-American Observatory in Chile which they use to estimate that there are approximately 3.2 million Earth approaching asteroids similar in size to the Chelyabinsk impactor.
My team the Catalina Sky Survey uses 4 telescopes, 24 nights per month, in the mountains north of Tucson, Arizona with the goal to provide warnings for people to stay away from doors and windows should a Chelyabinsk sized space rock be on an impact trajectory with planet Earth.
396 – Jupiter
Jupiter has been observed throughout human history and is so bright that you can even spot it under the artificial light dome of one of our cities. Even so it is less than 40 years ago that we were first able to view Jupiter in detail as the Voyagers streaked by it. Jupiter contains more than twice the mass of all of the other planets, dwarf planets, asteroids, and comets in our solar system combined.
Eons ago, our solar systems very own giant planet, Jupiter, appears to have cleared out the inner solar system leaving enough rocky debris to form Mercury, Venus, Earth, and Mars. Without Jupiter’s action our solar system is likely to have turned out like the more than half of the planetary systems which we have found which consist of non-inhabitable super Earth sized planets orbiting closely about their host stars.
In terms of the defense of planet Earth from impacting objects, Jupiter is a mixed blessing. It apparently deflects some of the long period comets out of Earth impacting orbits while sending other asteroids and comets our way. In 1770 a small comet came in from the outer solar system and passed near Jupiter. This encounter sent it straight towards Earth. Fortunately this celestial visitor missed humanity by about a million miles. After two orbits of the Sun this small comet once again passed near Jupiter and was ejected from the solar system.
Look up where to find Jupiter on the internet and observe it. Jupiter is an awesome sight in binoculars or a small telescope. As you view this gas giant think about the fact that it is likely the reason you have a place to stand and air to breathe.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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