(meteorobs) OT: SMART-1 lunar crash landing Sunday morning September 3

[Bruce McCurdy]

    Peter wrote:

>   So does anyone think we'll be able to see the resulting dust cloud? 
> According to the reports, impact is slated for Lacus Excellentiae at 06:41 
> GMT.

    Ejected dust clouds are close enough to on-topic in this forum AFAIC.

    Your time seems to be off by an hour. According to the ESA website, here 
are the three times that the spacecraft may hit the surface (due to certain 
errors in topology, etc. as noted):

Nominal -1      3 September 2006        00:36 UT        43.5° W 36.4° S
Nominal           3 September 2006        05:41 UT        46.3° W 36.4° S
Nominal +1      3 September 2006        10:46 UT        49.0° W 36.3° S


>   Given that this thing will hit at about 2km/s (approximately 1/30 the 
> speed of a Leonid), do we have any hope of seeing anything with, say, an 
> eight-inch reflector?

    An important factor is the exceedingly southern declination of the Moon, 
which is virtually at its 18.6-year minimum (-29°) on September 2. This 
means the Moon will be at a relatively low angle for anybody north of the 
tropics, and will set early. If this was a meteor shower, this would be one 
gibbous Moon that wouldn't cause much grief! Alas, viewing of the Moon 
itself, esp. for such a subtle event, is unlikely to be very good. At the 
"nominal" impact time, Southern California and Hawai'i might be about the 
best.

    For more, see:

http://www.zone-vx.com/alpo-smartimpact.html
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=39841

    Bruce
    *****