Planisphere you can print out yourself

A planisphere is a great tool that is not only useful while out observing but a valuable teaching tool.   Nearly all U.S. States and Canadian Provinces elementary curricula include the concept of changing night sky which returns the following year.  Planispheres are a great way to teach that.  The Lawernce Hall of Science has a great PDF file which can be printed on cardstoc, a project that most Elementary aged students can handle.

Works best if you print it out on cardstock, but makes a good classroom project that kids can actually use, courtesy of the

how fast are we moving?

If you’ve ever centered your telescope on an object turned to talk to someone and looked back only to find that that object has moved out of your eyepeice, you’ve seen the earth’s movement in action, but how fast are we moving? There are 3 answers:

The earth rotates every 24 hours, a point on the equator is traveling about 1000 miles per hour (slower as you move away from the equator).

The Earth follows ~600 million mile path as it orbits the sun each year. So that motion is about 66k miles per hour.

Our solar system also orbits the center of the milky way galaxy along a path roughly towards Vega in the constellation Lyra at a speed of about 43k miles per hour.

From: Universe in the Classroom No. 71 • Spring 2007, courtesy Nasa

for science educators, outreach volunteers, amateur astronomers, or maybe just me