Podcaster: Dr. Al Grauer
Title: Travelers in the Night Eps. 223E & 224E: Fragment & Enceladus’ Ocean
Organization: Travelers in The Night
Description: Today’s two stroy:
- Richard Kowalski discovered 2016 dp! Millions of years ago two large asteroids collided in the asteroid belt. Pieces were sent flying in all directions. A few of them were put into orbits which rise high above and below the plane of the solar system as they continued to travel around the Sun. A fragment is discovered from a collision long ago as it comes near the Earth. Fortunately this space rock will not strike the Earth anytime soon. It will continue to orbit the Sun in the silent vacuum of space until it has a collision with another asteroid or comet in the far distant future.
- Pound for pound Saturn’s moon Enceladus is the brightest object in our solar system. It is so shiny that it reflects most of the sunlight that strikes it. Since Enceladus absorbs little sunlight its surface is 330 degrees below zero Fahrenheit. Below its icy exterior the story is very different. It appears that Enceladus has an ocean of liquid water. What Next?
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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223E – Fragment
Millions of years ago two large asteroids collided in the asteroid belt. Pieces were sent flying in all directions. A few of them were put into orbits which rise high above and below the plane of the solar system as they continued to travel around the Sun.
Recently my Catalina Sky Survey teammate Richard Kowalski discovered one such a fragment. He was observing with a 60 inch telescope on Mt. Lemmon in Arizona when a fast unknown moving point of light appeared on a set of his images. Over the next six nights this new object was tracked by telescopes in Arizona and Texas.
Scientists at the Minor Planet Center used these data to determine it’s orbit, estimate it’s size, and give it the name 2016 DP.
Richard’s new Earth approaching asteroid, 2016 DP, is about a quarter of a mile in diameter, orbits the Sun once every 377 days, and can come to about 13 times the Moon’s distance from us. It is categorized as a Potentially Hazardous Asteroid which means that asteroid hunters will need to keep special track of it. In 1943 Richard’s large space rock came much closer to Earth than it did in 2016 when he discovered it. In 2062, 2016 DP, will come much closer to our sister planet Venus than it ever does to Earth.
Fortunately 2016 DP will not strike the Earth anytime soon. It will continue to orbit the Sun in the silent vacuum of space until it has a collision with another asteroid or comet in the far distant future.
224E – Enceladus’ Ocean
Pound for pound Saturn’s moon Enceladus is the brightest object in our solar system. It is so shiny that it reflects most of the sunlight that strikes it. Since Enceladus absorbs little sunlight it’s surface is 330 degrees below zero Fahrenheit. Below its icy exterior the story is very different.
For almost two hundred years since William Hershel discovered Enceladus, little was known about this point of light orbiting the distant planet Saturn. The situation changed when the NASA Cassini spacecraft began to take pictures as it orbited the ringed planet. Scientists were amazed when Cassini images showed plumes of gas being ejected into space from Enceladus. In the past ten years a number of spacecraft flybys have been used to uncover evidence that it is likely that this icy moon has a layer of liquid water beneath its surface.
We know that on Earth life abounds near volcanic vents on the ocean floor. Could such a situation exist on Enceladus? This is a tough question to answer about an object whose diameter is about the width of the State of Arizona and never gets closer than about 3/4 of a billion miles from us. Recently Dr. Christopher Glein and his team of researchers used Cassini spacecraft observations to find some interesting clues about Enceladus’s oceans. Their data suggests that what is happening on this tiny moon of Saturn is similar to what we find near the low temperature hydrothermal vent field called the lost field in the Atlantic Ocean. What next.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
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