View Full Version : Moon Occults Asteroid – Boston Graze – Jan 20

2012-Jan-16, 03:55 AM
I predict an occultation of Asteroid 20 Massalia by the 10% illuminated waning crescent Moon during the morning of 2012 JAN 20. In the United States the occultation will only be visible on the eastern seaboard shortly after the Moon rises yet before the Sun rises. Canada will be shut out, but the Caribbean and northern South America will be in the predawn occultation zone.

The northern graze path will pass north of Boston. From that location the graze will occur while the magnitude 12.0 asteroid has risen to only about 3° above the southeastern horizon. During a graze an occulted body appears to wink on and off as lunar hills and valleys pass by.

I’ve created three related graphics. The first is an occultation map showing the two graze paths. A full occultation will occur for observers between the paths. The second is a preview with data for Saugus, Massachusetts on the northern graze path. The third shows a view of the Earth and Moon from the asteroid, and includes Besselian elements in the format of Jean Meeus.

My graphics can be seen at www.CurtRenz.com/moon

This will be a challenge for even the most experienced observers. Nevertheless, photos and descriptions of the event will be welcome additions to this thread. Precise timings would be especially appreciated.