Hi All, An off-topic tidbit to file away for later this year: the Apollo asteroid (or is it an Aten?) 1999 MN is going to transit the sun on December 6th from around 8:20 to 11:50 UT. This is the only asteroid I've found which transits the sun as seen from earth this year. Unfortunately, this tiny asteroid is far too small to be visible in silhouette, as it will be at a range of some 70 million miles. Even if it were as large as a kilometer in diameter (which it isn't), it would only subtend 1.8 milliarcseconds. (It's probably only a couple hundred meters across). So I guess the event falls into the category of "astronomical footnote". A geometric curiosity, but not an observable one. With the inherent atmospheric limitations of ground-based telescopes, I wonder what the minimum detectable spot size would be for an instrument observing the sun? The Big Bear Solar Observatory has a 26" reflector, and there are images on their website with pixel resolutions of 0.25 arcseconds (which means objects half this size could be easily detected). 125 milliarcseconds corresponds to a 1-km asteroid at a range of 1.65 million km. Cheers, Rob ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Tue Mar 20 2001 - 18:23:29 PST