--- Joe Bauman <bau@desnews.com> wrote:
I appreciate the beiefing on seeing. But how did Mars look? Thanks, Joe
I was using a club loaner 6" Meade DOB. Mr. Jongwong (Kim) was using a 10" Meade DOB. Since we did not have equatorial tracking, the smallest practical lens we could use was a 4mm with a broadband LPR filter at around 275x (assuming an 1100mm f/l for these scopes). Higher magnifications appeared possible, but the constraint of drift limited increasing magnification with a Barlow. The LPR reduced Mars's glare and brought out surface color. Views with a 9mm lens and without a filter (120x) also gave good detail, but with an undersized TFOV for Mars's disk. The views were pretty similar to what is seen in the S&T Mars Simulator, with less contrast detail between the surface albedo of the features. For example, Hellas Basin was not visible as a distinct feature. The macro features at around 1:00am remain Syrtis Major, Sinus Meridiani and the north polar cap. During moments of calm, details in Sinus Meridiani on Mars's apparent central meridian would snap into focus around the 1-2 arcsec diffraction limit for these scopes. But the level of detail was nothing like what is seen during similar moments of calm in the SLAS's 32" with a 1/4" diffraction limit. The LPR filter at 275x adds a rusted color to the prevailing surface soils of Mars. I had the impression I was looking at a giant bowl of rusted sand, with some darker continental plates sticking out above the lower elevations filled with oxidized soil. The general east-west orientation of these higher continental masses make me wonder what the boundaries of the Martian tetonic plates look like - back when the archaean Mars was tetonically active. The most inspirational part of watching Mars for an about hour is the real sense that you are looking at another planet which re-enforces that you are standing on a planet. Although I suspect most people after 5 minutes go "seen that, done that, been there." It's one thing to be told that you live a planet, to look at models of the solar system when you are kid, and another thing to directly experience it in the eyepiece. The session charged me up to try and observe,as the season progresses, in the early morning before sunrise to see what other features rotate into view. I looked again at about 3:00 when Syrtis Major was starting to rotate out of view. Confirming a recent hoax internet email, at 275x, Mars indeed does look about as large as Moon seen with the naked-eye. -:) Unfortunately, the rovers were not visible. -:) - Canopus56(Kurt) __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com