Podcaster: Dr. Al Grauer
Title: Travelers in the Night Eps. 35 & 36: An Asteroid With A Ring & Earth and Moon as Evening Stars
Organization: Travelers in The Night
Link : Travelers in the Night ; @Nmcanopus
Organization: Travelers in The Night
Link : Travelers in the Night ; @Nmcanopus
Description: Today’s 2 topics:
- Chariklo is an asteroid which orbits the Sun between Saturn and Uranus every 63 years. It was discovered in 1997 by James Scotti an astronomer with Spacewatch on Kitt Peak in Arizona.
- The Earth is the brightest object in the Martian sky. Observers on Mars see our Earth and Moon as either a double morning or evening star because Mars is further from the Sun than our planet.
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:
23E – An Asteroid With A Ring
Saturn had a strange appearance in Galileo’s telescope. At first he described it as being a composite of three objects. A few years later, better telescopes showed a beautiful ring system surrounding Saturn. For more than 350 years Saturn was the only known planet with rings. Now we are aware that Uranus, Jupiter, and Neptune also have ring systems.
Chariklo (“KAReekloe”) is an asteroid which orbits the Sun between Saturn and Uranus every 63 years. It was discovered in 1997 by James Scotti an astronomer with Spacewatch on Kitt Peak in Arizona.
At eight different observatories in Brazil, Argentina, Uruguay, and Chile , in June of 2013, Astronomers were timing the dip in light when the asteroid Chariklo (“KAReekloe”) passed in front of a star. They sought to obtain a better value for its 140 mile diameter. To their amazement they also obtained dips in light before and after the main body passed in front of the star. These extra dips were caused by two narrow icy rings 4 and 2 miles wide respectively. These orbiting rings are separated by a 5 mile wide gap.
A careful study of Saturn’s rings has shown that some of them are shaped and maintained by its moons. Neptune’s rings are kept sharp by some of its moons. This implies that the asteroid Chariklo (“KAReekloe”) has undiscovered moons which have sculptured its rings.
A number of asteroids have been observed as they pass in front of a star. Chariklo (“KAReekloe”) is the first to show a ring system. Perhaps there are others.
24E – 36- Earth and Moon as Evening Stars
From our moving platform on Earth we see the bright planet Venus either as a morning or evening star. This happens because the planet Venus is on an orbit closer to the Sun than ours. This geometry means that Venus never gets farther than 47 degrees from the Sun in our sky.
The Earth is the brightest object in the Martian sky. Observers on Mars see our Earth and Moon as either a double morning or evening star because Mars is further from the Sun than our planet. Recently the NASA Curiosity Rover took a mind expanding image of our Earth and Moon from Mars. Take time to look at this image and ponder the fact that all of the human race is on that bright dot and that the furthest we have traveled in space is between those two points of light.
A human with normal vision standing on Mars would see the Earth and our Moon as a double evening star. An observer on Mars would also see the distance between the Earth and Moon change as they revolve around a common center of gravity.
Perhaps one day humans will set up a base on the red planet and will be able to view this beautiful celestial display.
At this point we do not know if life ever existed on Mars. We do know that liquid water has existed there in the past. Mars has a surface area about the size of the dry land on Earth. Our robotic emissaries are currently exploring Mars. You can participate in the discovery process using the NASA Curiosity Rover website via the internet. Try it. It is truly a reality based imagination stimulating experience.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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