For those of you with telescope apertures of 200mm or greater and not easily frustrated, now is a great time for observing and imaging Mercury in the eastern dawn sky.
Tomorrow morning, the planet presents a 40% crescent phase with an angular diameter around 8.4 arc seconds (about 2" greater than Mars appears at present). It will be at Central Longitude 177 degrees presenting a view not imaged by spacecraft previously. If the seeing is exceptionally good then you may see some fleeting low albedo surface markings. A red Wratten filter #25 or #23A will help improve contrast and will work well for an image if you're game to try. I'd be interested to see any results (no matter how bad) from forum members. Of course tomorrow morning is not the only opportnity as good observations can be made into the month of May however the planets apparent size is shrinking daily.
