Organization: Travelers in The Night
Description: Today’s 2 topics:
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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425 – Greg’s Comet
My Catalina Sky Survey teammate Greg Leonard was searching for Earth approaching objects with our 60 inch telescope on Mt. Lemmon, Arizona when he discovered an interesting new comet moving through the constellation of Leo. After Greg posted his discovery observations on the Minor Planet Center’s Near Earth Confirmation Page it was observed over the next 3 weeks by 10 different observatories around the world. These data were used to calculate the details of the new object’s 51 year path around the Sun and give it the name Comet C/2017 W2 (Leonard) . Greg’s newly discovered comet’s orbital plane is almost at a right angle to paths of the planets and most of the asteroids so that it spends most of it’s time in the lonely space high above or far below the rest of the members of our solar system. Riding with Comet C/2017 W2 (Leonard) would bring a space traveler into the inner solar system about once per human lifetime. Greg’s comet receives only mild solar heating since at it’s closest it is about 3 times further from the Sun than we are making it unlikely to ever be bright for human observers. At it’s furthest from the Sun, Comet Leonard is in a very cold region, receives less than 1% solar energy than we do, and and likely to have a surface temperature of about -300 degrees Fahrenheit. Greg’s comet is likely to remain as it is for eons since it spends so much of it’s time far from the Sun and the gravitational tugs of most of the rest of the members of our solar system.
426 – Rose Rules Again
Recently my Catalina Sky Survey teammate Rose Matheny discovered 8 new Earth approaching object candidates on a single night with our Schmidt telescope on Mt. Bigelow, Arizona. One of them, 2017 YO is a mile and a half diameter, main belt asteroid, while the other 7 are interesting Earth approaching objects. Another one of Rose’s single night discoveries is 2017 YM1. When Rose first spotted it this space rock was moving rapidly north, at 6.9 miles per second, away from the Earth in the constellation of Ursae Major. About 5 days earlier it had passed near both the Earth and Our Moon at which time it was too far south to be seen from Arizona. This space rock is about 92 feet in diameter, orbits the Sun once every 2.25 years, and can come to less than a tenth of the Moon’s distance from us. 2017 YM1 is about 1.5 times larger than the Chelyabinsk (Shell ya binsk) meteor which in 2013 broke many thousands of windows and injured 1,200 people. According to Perdue University’s impact calculator, a space rock like 2017 YM1 enters the Earth’s atmosphere once every hundred years or so with an energy of 250 kilotons of TNT, explodes into a cloud of fragments at about 73,000 feet, rains pieces onto the ground, and produces a sonic boom that would get your attention as it breaks a lot of windows. Asteroid hunter’s goal is to discover any such impactor days before it enters the Earth’s atmosphere so that people can be warned to stay away from doors and windows.
For Travelers in the Night this is Dr. Al Grauer.
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365 Days of Astronomy
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