Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 623 & 624: Arecibo & Incoming

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  • We all will miss this scientific treasure.
  • Greg Leonard discovered 623’ diameter 2020 XU6.

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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623: Arecibo

The National Science Foundation has announced that it will close and decommission the giant RADAR telescope at the Arecibo Observatory in Puerto Rico. The problem started in August of 2020 when a cable supporting the 900 ton science platform slipped from its socket and was made untenable when a second cable snapped. The decision to close the facility became necessary after engineers found that the telescope is undergoing uncontrollable collapse and that even if crews could safely repair all the damage the basic structure cannot be stabilized.

Whip lashing cables during an unpredictable catastrophic collapse of the entire structure make it life threatening for crews to try to shore up the support structure. For asteroid hunters the loss of the unique Arecibo RADAR Observatory will mean that scientists will no longer be able to routinely measure the size and shape of Earth approaching asteroids and/or if an asteroid is a single object or if it is an orbiting pair of space rocks. These are vital planetary defense pieces of information which are required to mitigate the disaster which could occur if and when asteroid hunters find an incoming object with our number on it.

The telescope’s giant 1,000-foot-wide dish became famous in the Jodie Foster film “Contact” and the James Bond movie “GoldenEye.”  For Puerto Rico’s island economy which in recent years has been battered by storms and Earthquakes, the 90,000 tourists per year who have visited the observatory were a significant source of revenue. We all will miss this scientific treasure.

622: Lonely Vigil

Recently my Catalina Sky Survey teammate Greg Leonard was asteroid hunting with our 60 inch telescope on Mt. Lemmon, Arizona when he spotted a moving point of light streaking at 6.9 mi/sec through the constellation of Canis Minor. Further observations by 3 other telescopes in Arizona allowed scientists at the Minor Planet Center to calculate the new asteroid’s 3.3 year orbit about the Sun, estimate it to be 623 feet in diameter, and give it the name 2020 XU6.

Nine weeks after Greg discovered it, 2020 XU6 becomes 231 times brighter as it passes about 10 times the Moon’s distance from Earth. Occasionally 2020 XU6 will come 10 times closer than that and be bright enough to be easily seen with a small telescope. Because of its size and ability to come close to Earth 2020 XU6 is classified by NASA to be a Potentially Hazardous Asteroid or PHA for short. Of the known 2,000 PHA’s only 38 of them are listed on NASA’s Sentry risk table which means that they have an extremely slight chance of impacting Earth in the next 100 years. One of them, Apophis, will come to less than 20,000 miles from the Earth’s surface on Friday April 13, 2029.

Apophis will be as bright as the stars in the Little Dipper and will appear to travel a full moon diameter in less than a minute. Greg’s discovery will not impact Earth in the foreseeable future, however, rest assured that asteroid hunters will continue to track it as it passes near Earth and Mars to make sure that 2020 XU6’s path does not change to put it on a collision course with Earth.

For Travelers in the Night this is Dr. Al Grauer.

End of podcast:

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