by Rod Pommier
Telescope and Mount: Celestron Compustar C14 Telescope/Mount with 2x Televue Powermate Barlow. Camera:Point Grey Research Flea3 Color. Date/Time: 2012-03-07 through 2012-04-17 at times indicated. Location: Pommier Observatory, Portland, OR, USA. Exposures: Left image, best 300 frames out of 1500 at 24 frames per second; center and right image, best 400 frames out of 3000 at 60 frames per second. Seeing conditions (Damian Peach Scale): Poor ( but clear weather in March and April is rare in Oregon, so some data are better than no data). Software, Firecapture, AS2!, Registax 6, Photoshop.
Description: Earth passed between
the Sun and Mars, known as opposition, on 2012-03-03 and made closest approach
on 2012-03-05. Around these times, Mars ‘disk is illuminated in full phase and exhibits
its greatest apparent diameter. Subsequently, Earth pulls ahead of Mars and we
look back on the morning terminator of a waning gibbous Mars whose disk shrinks
as it seemingly recedes in the distance.These images show that even small changes in disk
size have a profound impact on the apparent sizes of surface features, like
Acidalia Planitia, Margaritifer Terra,
Sinus Meridiani, and Syrtis Major, making them progessively more
challenging to capture in images.