Tuesday, September 02, 2008

September eNewsletter from the MN Planetarium Society

In this issue from the Minnesota Planetarium Society:
President's Message
ExploraDome Activities
September Skies 2008
Observe Four Moons of Jupiter
Ocean on Europa?

President's Message
We Need Your Help

We've made progress but we need your help immediately! On September 9, the Hennepin County Commissioners will vote on a go/no-go resolution for the Planetarium.  Please immediately contact your Hennepin County Commissioner (http://www.co.hennepin.mn.us/ under "Who is My Commissioner") and ask for their support of the project.  Because the County is looking to Minneapolis and the state to share operating costs, calls to City Councilmembers and legislators on behalf of the new planetarium will also be very helpful.  The resolution they will see is similar to the following:

That the Hennepin County Board support building a Planetarium on top of the new Central Library, contingent on:
*Securing other public sector operating support;
*Commitment by MnPS to raising the remaining capital funds;
*Development of a $4 million operating endowment (to be raised by MnPS);
*Legislative approval to extend the State bonding expiration date.

We are excited to be at this critical stage but please make that call.  Thank you!

Peggy Leppik, President, MnPS

ExploraDome Activities

In July, staff of the Minnesota Planetarium Society (MnPS) shared examples of our ExploraDome activities with colleagues around the world at the International Planetarium Society (IPS) conference in Chicago. Sally Brummel, Education Outreach Coordinator, demonstrated the programs that MnPS staff have presented to over 16,000 Minnesota students in the inaugural 2007-08 school year. Joel Halvorson, Program Director, engineered and monitored sessions on climate science and the James Webb Space Telescope that featured live remote presentations inside the Adler Planetarium's Space Theater using the domecasting capabilities of Uniview. (See next month’s issue for more about Uniview.) This allowed the scientists to present from their offices around the world to the IPS community without taking too much time out of their busy schedules for travel. Joel was recognized for his outstanding contributions to the domecasting community. Both Sally and Joel served as integral members of a panel discussion on planetariums as immersive learning labs.

We are now taking ExploraDome reservations for the 2008-09 school year!   http://www.mplanetarium.org/exploradomereservations.htm

September Skies

Early evening September skies bring us bright Jupiter, our feature this month, in the south at about 9pm. On September 9, watch the Moon join the king of planets in Sagittarius the archer (looks like a teapot). The bright Moon at that time will obscure the Milky Way but when looking at Sagittarius, you are looking toward the center of our home galaxy. Look directly overhead to see the bright star Vega. Twenty-five degrees east of Vega lies Deneb and about 35 degrees SE of Vega is Altair. Those three stars form the Summer Triangle. The Great Square of Pegasus gallops in the east. Find the Big Dipper over in the NW and follow its handle to “arc to Arcturus”, the orange tinted star in Bootes. September is a good time to wander out to Baylor Regional Park and join the Minnesota Astronomical Society (http://mnastro.org/onan ) for a public star party on September 6th and 20th.

Observe Four Moons of Jupiter

Sky & Telescope photograph by Richard Tresch Fienberg.

Jupiter does not travel around the Sun alone. Accompanying it are 63 moons (that we know of!). The four largest moons, Europa, Io, Ganymede, and Callisto were discovered in 1610 by Galileo, the first person to peer at the sky through a telescope and realize that objects orbit other worlds; Earth was not the only center of motion. These four "Galilean Moons" are big enough to see from your own backyard--with the aid of a pair of binoculars.  They look like stars lined up on either side of Jupiter.  If you don't see all four, that's because one or more may be behind or in front of Jupiter.  A reference guide such as this one from Sky and Telescope will help you identify the moons. Observe for two or more nights; you'll see the orbital system in action!

Ocean on Europa?

Europa is visible from Earth with binoculars, due to its large size (slightly smaller than our Moon) and high "albedo" (the fraction of sunlight reflected from the surface). Although our Moon appears bright to our eyes, its albedo is actually less than 10% (moon dust looks black! in the laboratory) while Europa's is over 60%.  This high albedo comes from its smooth icy surface, which overlays a possible ocean of water a couple of miles thick, located over 100 miles below the surface.  While Europa's surface is cold, -260F, its interior is heated by the stretching and relaxing of tidal forces from Jupiter and the other massive moons of Jupiter. NASA's aptly named Galileo satellite found further evidence for a slightly salty underground ocean on Europa from its magnetic field sensors. For further information, check out NASA's websites or http://www.space.com/searchforlife/seti_phillips_europa_040226.html .