Monday, November 07, 2005

20051105 - Accretion from sidewalk astronomy

Session Name: 20051105.1330

Note: Cloud cover passed through resulting in 2 sessions. The first was from 1:30 ~ 2:15pm and the second was 3:40 ~ 7:30pm. Venus was obviously naked eye during the second session.

Accretion- growth by accumulation and adhesion.

Yes, that sounds just right to describe a process that occurs from sidewalk astronomy in Central Park on a Saturday afternoon. Initially one or two passersby stop and ask what's of interest. I point out Moon and Venus in the sky. I ask if they can see them naked eye and invite them to the binocular eyepieces. In spite of the lack of contrast, they marvel at the magnified sight and relief often present on a waxing Moon. Today, one needs to observe with a critical eye just to make out Mare Crisium. I see Venus naked eye and describe her location relative to Moon - about 5 moon lengths at 1 o'clock. Many are able to spot it naked eye and thrilled by the fact that one can see a planet during the day. I adjust the binoculars focused on Venus, on casual glance she is clearly last quarter phase. "It looks like a little moon." "Exactly."

These folks stand around asking questions and share stories of their contact with astronomy. Soon enough another group of people will stop and question what is going on. I pause waiting to hear if one of the prior arrivals shares what’s going on, which they often do. It's the Moon and Venus as they gesture towards the sky. The amateur astronomer can only smile at the fact that the outreach is effective. Soon enough this small mass acquires more energy as it grows, gravitationally attracting others with curiosity and interest. The gravity well is centered on a pair of tripod-mounted binoculars as the center of mass. An observer will even see that among the chaos a hint of order can be recognized. The crowd rotates around the bins in a counterclockwise movement, either to allow someone else to have a look or they orbit to the front of the bins to see the glass.


Globulars, persons who stick but at a distance safely from the center, but remain attracted. They have been around a while, and they, too can describe what is happening in the sky, attracting questioning passersby. The globular’s influence sometimes attracts these interlopers enough to change their direction towards a new center of gravity.

Some persons have a visible outburst at the eyepiece, like a supernova explosion, energy and matter to cause new stars form. The crowd grows larger and larger. There is a lively spirit here on Earth.

Okay enough of that.

One thing I like about the tripod-mounted binoculars is the convenience of the Bogen tripod. Children come by with parents and it is simple enough to readjust to their heights. After the children get to look, the adults have no problem stooping over to get theirs in. Also, with the mutliple shoes, I can swap bins for a 22x magnified image or a 7x wide field view. The wide field helps those that don't see Venus right away but now get an idea of where to look.

Check out Ian Musgrave’s photograph of Saturday’s at Astroblog. His image appears different from our view on Saturday, probably because his is of the setting Moon in the southern hemisphere. We would later watch Moon set into one of the buildings. Fast action, similar to a sunset, but into the building. As it continued to sink, the lower horn appeared partially between two buildings. One of the buildings reflected Moon on the other building, appearing as if we could see Moon through the windows of that second building.