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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323 – Big Splash
To discover what would happen if an asteroid were to strike a large body of water, Dr. Galen Gisler led a team of scientists who used high performance computing facilities at Los Alamos National Laboratory to calculate and visualize a 3-D model of an asteroid entering the Earth’s atmosphere over one of the world’s oceans. These efforts won them the Best Visualization and Data Analytics Showcase award at Supercomputing 2016. Reality is that what happens depends upon the mass, size, speed, angle of approach, and composition of the impacting object. Galen’s group of scientists documented the hunch that since an asteroid strikes the water at a single point, it only effects the immediate region around the impact point, whereas to create a tsunami, you need something like an under water landslide which disturbs an entire water column from the ocean floor to the surface.
Impacting stony asteroids less than the size of a football field are likely to explode in the atmosphere. One several hundred yards in diameter is likely to reach the surface making a splash that would send up billions of tons of water into the atmosphere and create waves 1,200 feet high which would quickly dissipate and are no threat to land many miles away. Water is a powerful green house gas when blown into stratosphere could remain for months or years and would have a significant effect on weather and climate. An impact near the coast would be an entirely different situation and would be very dangerous to nearby human populations.
324 – Newborn Planets
The ALMA radio telescope located in the Atacama desert of northern Chile is able to see the faint millimeter wave length glow emitted by gas molecules and dust particles in the disk of material surrounding the very young star named HD 163296. This solar system in formation is located about 400 light years away in the constellation of Sagittarius. HD 162396’s age compared to our Sun is like that of a 3 day old human baby compared to a 65 year old adult.
Recently Dr. Andrea Isella of Rice University headed up a team which analyzed ALMA’s images of the proto-planetary disk of material surrounding HD 163296. Their work, published in Physical Review Letters, suggests HD 163296’s rings, in both the dust and CO gas, with gaps of material in between them, are consistent with two Saturn sized proto-planets plowing through the dust and gas, adding material to themselves, as they increase their growing masses.
We see a similar situation in Saturn’s ring system where some of it’s smaller moon’s produce rings and gaps.
Astronomers will need to obtain more data on the proto-planetary disk system surrounding HD 163296 to be sure that what they are seeing are new planets forming far from their parent star and not some other physical or chemical phenomena that occurs in baby solar systems.
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365 Days of Astronomy
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