Mars invades SF too

by Jane Houston Jones

We set up telescopes for sidewalk astronomy last night at 17th and Guerrero streets in SF. We were helping out a pro-literacy art exhibit opening at a small gallery at 483 Guerrero Street. It's a neighborhood we've been wanting to sample for sidewalk astronomy because the Mission has the best weather in the city, and the neighborhoods hops with people until late. Shirtsleeve weather and over 200 visitors for Mars views between 10:00 p.m. and midnight. We had our 12.5 inch f/5.75 Litebox out for sidewalk astronomy and Mars looked great at 125x using a 16mm old type 2 Nagler eyepiece. We'll be back to close out the exhibit on September 12th, at this location too, when the moon and Mars will be out.

The dark circular feature on the central meridian at 11:00 p.m. (CM about 100 at the time) closer to the south polar cap than to the north polar region of Mars was Solis Lacus, the "eye" of Mars. In the northern hemisphere, the Tharsis volcanic area was indeed visible, with Olympus Mons nearly at the north pole area, but these usually show up as white cloud tops features, not dark features.

I saw the "eye of Mars" black spot in a 60mm cheapo refractor at less than 50x at Fremont Peak Thursday night, too. It was really impressive in the 30-inch as well as in our 7-inch refractor, too, before clouds took over at about midnight.