Welcome to the Tri-Valley Stargazers Astronomy Club's web site. There is a lot
of information here on the many activities of the Tri-Valley Stargazers
(TVS). Learn why you should join the club to get the most out of your
amateur astronomy hobby in the east San Francisco Bay Area.
Next Public Meeting
Speaker: Dr. Richard G. Kraus
Vaporizing Planets and Raining Iron
Friday, August 21, 2015
Doors open at 7:00 p.m.
Show & Tell starts at 7:30 pm
Unitarian Universalist Church
1893 N. Vasco Rd., Livermore
Next Board Meeting
Monday, August 24, 2015, 7:30 p.m.
Round Table Pizza
1024 E. Stanley Blvd, Livermore
Members are always welcome at board meetings. Pizza is optional.
The Latest News & Upcoming Events
In this presentation Dr. Krauss will discuss his team's recent discoveries about processes occurring during Earth's formation,
which was presented in their Nature Geoscience article Impact Vaporization of Planetesimal Cores in the Late Stages of Planet
. He will begin by presenting a bit of background for how planets form. Then he will discuss the importance
of understanding high velocity impact events, as they played a tremendous role in shaping the solar system that we see
today. However, the understanding of these impact events is based upon the intuition gained from running computer
simulations of these high velocity collisions (as they are far too energetic to simulate in the lab). To better
understand these impact events, we need better models for how materials behave at these extreme conditions, in
particular for materials like iron. At the Sandia Z machine, his team developed an experimetnal technique to understand the
process of impact induced vaporization, and they used it to determine the critical impact speed to vaporize iron cores
(it's lower than one would have thought). Finally, he will discuss how this improved understanding of the physics of
impacts, has important implications for understanding the timing of Earth's formation and the evolution of our solar
Rick Kraus received his undergraduate degree in Physics at the University of
Nevada, Reno. In 2008 he received an MPhil in Physics from the University of
Cambridge, UK and in 2013 he received his M.S. in Applied Physics and Ph.D. in
Earth and Planetary Sciences from Harvard University. His thesis research was on
the thermodynamics of planetary impact events with a focus on impact induced
vaporization. In September of 2013 he joined the HED Shock Physics group at LLNL
as a Lawrence Postdoctoral Fellow. He is currently a research scientist in the physics
division focusing on the high pressure melting properties of materials.
The Jack Marling scope is back in operation at H2O!
The Jack Marling 17.5-inch telescope is back up and running
at H2O. Chuck and Roland reinstalled it on May 6, and
it went back into service for the first time at the H2O Open
House on May 9. The mount is non-motorized for now, but
it moves smoothly by hand and any vibrations now seem
to dampen quickly. Those of us attending the Open House
were treated to outstanding views of spiral galaxy M51 and
globular cluster M3.
Upcoming star parties
We have planned the following star parties:
- Saturday, September 19, Tesla Winery Star Party, 8:00-12:00
- Late September, Green Elementary School, details TBA
- Friday, October 2, Pleasanton RADD Star Party
- Saturday, Ocotber 17, Tesla Winery Star Party, 8:00-12:00
for further information.
TVS Logo Wear
You may have seen some TVS members wearing shirts and jackets
embroidered with the TVS logo. If you are interested in obtaining an
embroidered logo item, you can do so by ordering whatever you would like
Land's End's Corporate Sales
section and specifying TVS logo #0118948. You will need to set up an account, which will
ask for the logo number and the TVS customer number (3452021).
TVS has also set up shop at
for members to buy non-embroidered TVS logo wear. You can have the TVS
logo put on t-shirts, mugs, buttons, hats, coasters, etc. You buy
through Cafepress, and Cafepress sends TVS a portion of the proceeds.
Visit the web site to see all the TVS logo possibilities.