Mount Tamalpais Astronomy Program 5/19

From: contacts-bounces@aanc-astronomy.org [mailto:contacts-bounces@aanc-astronomy.org] On Behalf Of Tinka Ross
Sent: Thursday, May 03, 2007 7:58 AM
To: 3tam
Subject: [AANC Contacts] MT TAM ASTRONOMY PROGRAM 5/19Mt Tam Enthusiasts – Well, the rain came in April, but we have high hopes for May. Please join us for our first astronomy program for 2007 on SATURDAY, MAY 19 AT 8:30PM in the Mountain Theatre on Mt Tamalpais.

Dr. Scott Sandford, from NASA-Ames Research Center, will give us an overview of the Stardust Mission and an update on what has been learned from the comet sample it returned to Earth from Comet 81P/Wild2.

Weather permitting, the talk will be followed by observing in the Rock Springs Parking Lot, with the San Francisco Amateur Astronomers.
This a FREE program, sponsored by Mt Tamalpais State Park, open to the general public. Student and youth groups are encouraged to attend.
Dress warmly, bring a flashlight and car pool if possible. More information and directions are on our website: http://www.mttam.net. If the weather is questionable that day (dare I even suggest it?) call the hotline 415-455-5370 after 3:00pm for an update.

Thanks for sharing this information.

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Mercury: Crunchy on the outside, with a soft, chewy center

An NSF Press Release indicates that astronomers Jean-Luc Margot of Cornell University, Stan Peale of the University of California, Santa Barbara, Ray Jurgens and Martin Slade of the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., and Igor Holin of the Space Research Institute in Russia will report their findings in the cover story of the May 4, 2007, journal Science.

These scientists used ground-based radio telescopes to measure minute wobbles in the motion of the planet Mercury, and have discovered strong evidence that Mercury has a molten core.

“So what?” you say? This is cutting edge science, and an incredible leap forward in the remote detection of geologic features on other planets. This technology, now that it has been developed, could be refined and perhaps eventually be used to look for similar conditions on extra-solar planets.

This is the kind of stuff that the average person-on-the-street may think “Why is this a big deal?”.   I’m thinking “Get out of the street before the bus runs you over!”.  It is a big deal.   We now have another tool in our arsenal that can determine if a planet is earth-like.   Science like this is used to test our assumptions.  There was a question up in the air: Does Mercury have a solid core, or a molten core?  Some thought it would be nearly pure iron, and therefore solid.  Others thought it would be molten due to the presence of contaminants like sulfur (which would lower the melting point of the core).  It looks like the molten-core theorists are on the right track.

This will tell us more about the formation of our solar system, and possibly the formation of other solar systems.  Perhaps we can now look at Venus, and Mars to determine if they have solid or molten cores.