Scale Model of the Earth and Moon

scale_earth_moonAs well as the scale model of the solar system in my previous post, I will be using a scale model of the Earth and Moon in order to show distances, as well as demonstrate eclipses.   For this model, I used a 1″ wood ball, and a 1/4″ wood ball.  I drilled holes in them, and glued them onto bamboo Shish Kabob skewers.

Then I painted the moon a gray that my wife had in her craft paints, and  also painted the ‘Earth’ to vaguely resemble a globe.  I can’t say that I’m an artist.  If I work really hard, I may someday be good enough to be fired from a sweatshop operation in China.

To use this I’ll be using a pair of spring clamps, and a yardstick (or reasonable approximation thereof).  The proper distance between the Earth and Moon at this scale turns out to be 30 inches.

Scale Model of the Solar System

At Fremont Peak Observatory this Saturday, I will be doing an activity for the kids that involves a large scale model of the solar system.  We’re not going to do the entire solar system, just some of the inner planets.

I really wanted to make the scale model of the Solar System as outlined in “Worlds of the Solar System” activity on the NASA Night Sky Network, but the materials for it turned out to be much more difficult to obtain than I anticipated.

You can in fact order ‘Dylite’ (a.k.a. ‘Smoothfoam’) balls in various sizes… if you are willing to order multiple units.  I don’t want twelve of the  1 & 3/8 inch balls, I want two!  The local crafting store has a very limited selection of these.  I could get the 4-inch ball but not the 3 & 7/8 inch one.  Plus, they’re expensive!

So, a different solution needed to be found.

Being pressed for time, and unable to find the materials, I resorted to rendering the model in 2D instead of 3D.   In the PDF file is a handout page with correctly scaled pictures of the planets (Mercury, Venus, Earth, Mars, Saturn, Jupiter, Uranus, Neptune).  Dwarf planets need not apply, apparently, but they are too small to be made in this 2D model anyway.

In order to accomplish my project, I printed two copies of the handout page in color.  I then used a glue stick to glue the back of the planets (before I cut them out) and pasted each sheet onto cardstock (a file-folder would work here too).  After letting them dry for a while, I then used scissors and a craft knife to cut out the pictures.

At this point, I had two pictures of each planet.  I quickly learned in the next step that the smallest planets (Mercury and Mars) are too small to do this next step.  The larger planets worked fine, and the larger rocky planets (Earth and Venus) could go either way .

The next step is to glue the two pictures of each planet together around bamboo Shish Kabob skewers (which I stole from the drawer in our kitchen).  For this step I recommend using ordinary white glue.  It wouldn’t work on regular weight paper, but on the cardstock it softened it up enough to mold the cardstock around the skewers.  This works great for the gas giant planets.

When I got down to Venus and Earth, however, it was much more difficult because of the small sizes of the circles.  When I got down to Mars, it was impossible.  I resorted to using a single cut-out, and placing a drop of glue on the back, then laying the tapered tip of the skewer into the glue.   I repeated this for Mercury.

In retrospect, this would work well for Venus and Earth as well.  If you wanted to, there is really no reason why the planets have to be double-sided, it just seemed like a good idea at the time.

I used the label page printed on plain paper, and glued the labels around the skewers using a glue stick.

I’m actually fairly proud of the result.

Fremont Peak impending closure

In an effort to close California’s significant budget gap, Governor Arnold Schwarzenegger has significantly cut funding to the state park system. This is forcing the California State park system to propose closing several state parks, including Fremont Peak State Park, which is where the FPOA Challenger telescope lives.

This closure, if it stands, would be a significant blow to amateur astronomy and to astronomy education in the San Francisco Bay Area.

The Fremont Peak Observatory is maintained by over a hundred amateur astronomers who serve the entire region, providing educational opportunities including viewing opportunities, classroom visits, participation in scientific research projects, internships for community college students, lectures, and educational projects and activities. Local schools from elementary classrooms up through community colleges use the resources provided by FPOA.

In a letter to members FPOA president Doug Brown asks for help to:

identify decision-makers,
draft appeal letter templates for distribution to our members and customers, draft media releases,
or make effective contact with representatives and media

CAP Journal #5

I’m a bit late on this, but the 5th issue of  Communicating Astronomy with the Public Journal is online.  If you haven’t read this online publication yet, and you are an amateur astronomer who does public outreach, or if you are an educator who is interpreting astronomy for the public or for a classroom, this is an excellent way to keep up to date on current astronomical events, and how to communicate those events to the layperson.

IYA2009 kickoff at U.C. Berkeley

Received in email from the AANC mailing list:

The International Year of Astronomy 2009
(IYA2009) is a global celebration of astronomy and its contribution to
society and culture, emphasizing education, public participation, and
the involvement of young people. The grand opening ceremony will be held
Jan. 15 and 16 in Paris at the headquarters of the United Nations
Educational, Scientific and Cultural Organization (UNESCO).

While hundreds are expected to attend the Paris event, including members
of royal families, ministers, Nobel Laureates, scientists and students,
many national and regional events also are scheduled.

UC Berkeley’s Department of Astronomy joins the international
celebration with talks on the science and history of astronomy on the
third Saturday of each month, from 11 a.m. to 12 noon, including two
talks on April 18, UC Berkeley’s annual CalDay open house. Next month’s
talk, scheduled for Feb. 21, is “Black Holes: Monsters Lurking at the
Centers of Galaxies,” by theoretician Eliot Quataert, professor of
astronomy and physics. Upcoming topics include dark matter, dark energy,
the search for extraterrestrial intelligence, star birth and their
explosive deaths, the solar system, and Galileo Galilei, who first
turned a telescope on the heavens 400 years ago.

To kick off the celebration, UC Berkeley will be hosting a lecture, “The
Search for Habitable Planets and Life in the Universe” in which Geoffrey
, UC Berkeley professor of astronomy, director of the Center for
Integrative Planetary Science, and the world’s foremost planet hunter,
will be speaking. It will take lace this Saturday, January 17th at 11
a.m in room 100 Genetics and Planet Biology Building UC Berkeley. The
building is located in the northwest corner of the campus:

For a complete list of the year’s talks and other UC Berkeley activities
planned to celebrate the International Year of Astronomy, link to For more information on IYA2009, link to

Thank you,

University of California, Berkeley Astronomy Department