by Akkana Peck
David North wrote:
However, around 1am we got some very nice moments of steadiness, and through several telescopes got solid views of the dark "rim" between the Vastitas Borealis and the pole. Reportedly the best views were through the 30-inch Challenger telescope, but I wasn't smart enough to make the stroll up to see it.
I made the stroll, and was glad I did. The 30" was stopped down to 10", and was giving very nice views, including a sharp dark line around the NPC, separated by a thin lighter area from Vastitas Borealis (okay, Mare Boreum on the ALPO map, but I like the name "Vastitas Borealis" better). Unfortunately I forgot to ask what eyepiece was in place; it was perhaps somewhere around 350-400x?
Although the seeing wasn't tremendously steady, it was a night for aperture, and in addition to the stopped-down 30", I saw excellent views in a C-14, a 12.5" Newtonian, and my own 13.1" Newtonian at around 250-300x; I could see more detail in all of the big 'scopes than I saw in a 6" refractor. This is unusual in my experience; I usually see more detail on planets and the moon in the refractors, especially with binoviewers, in the sketchy seeing I usually encounter. But this was my first chance this opposition to compare Martian views in many telescopes at once, since most star parties here in the bay area have been clouded out for months. It was also my first look at Sinus Meridiani; I'm looking forward to getting a better look at it when it rotates around to face us again.
Bill Arnett wrote:
It was one of John Gleason's "lesser" instruments :-) I thought it was every bit the equal of the view with the 30" (stopped down to an unobstructed 10"). But that might be because 1) John was using a binoviewer and 2) the eyepiece location on the 30" is usually so awkward that it's hard to get comfortable and take a long look.
That's also surprising; usually Bill is the one who sees more detail through large aperture and I'm the one who prefers the smaller-aperture view. Maybe a 5'2" observer is more used to observing in uncomfortable positions (standing on tiptoe, hanging onto ladders, sliding off the sides of observing chairs :-) so I wasn't as bothered by the odd angle of the eyepiece.
Rich Neuschaefer asks:
Last Friday and Saturday nights (Apr 16 &17) the eastern and western (leading and trailing) limbs of Mars looked white or gray white. The size of the white areas would change, sometimes more and sometimes less. At times they seemed as large as the width of northern part of Syrtis Major. What were these whiter areas?I thought maybe this brightening of the Martian limbs was from fog or haze in the Martian atmosphere. Maybe it was just the light reflecting off the Martian atmosphere?
I didn't notice that, but I neglected to try colored filters (I was enjoying the white-light view so much) and never made it over to where Rich & co were so I didn't get a chance to experience the 7" view, alas. I know Rich saw quite a bit more detail than I did (I didn't see any of the "bays" or notches in Syrtis Major which Rich reported seeing). I have seen what I think are limb clouds (extensive light areas which become much more prominent using a blue or violet filter) with my 6" reflector.