On Astronomy Day, I went to the Foothills Park star party. It was the first
time I'd been to that site, and it was really nice. The observing site at
Vista Hill is a perfect place to set up for the moon, planets, and bright
DSOs. I couldn't help repeatedly walking over to the crest of the hill and
looking eastward at the view of the Bay Area. Even though I've seen the
same view from higher up on Black Mountain, it was just mesmerizing. Hard
to believe that I've been a Palo Altan for six years and never been up
there.
The sunset and twilight were lovely. It was very clear, warm, and dry. A
little hazy, but one could still see Mounts Diablo, Tamalpais, and Hamilton
from the vista point.
I set up the ED80 on my CG-5 mount, the same as I had the night before at
Hogue Park. George Feliz and I did a bit of a 'small refractor shootout'
between the ED80 and George's TV-85. Here's my impression in a nutshell:
The performance of the two scopes was very similar, although at high power
(say, 120x or 240x), the diffraction rings were slightly more noticeable in
the ED80. This was on targets like Castor and Izar. We couldn't quite
explain the difference, given how similar the apertures are, but we both
noticed it. That said, the other aspects of the performance seemed quite
similar, on the Moon and Jupiter.
During twilight, the seeing was 3.5 to 4 out of 5. Very, very nice. I
started with the moon, of course.
I began, as usual, with a 'full-disc survey', using the 12mm type 4 Nagler
(50x). The 'star' crater was Theophilus. The tip of its central peak was a
perfect, infinitesimally small, starlike point of light. Mare Crisium had
become essentially an albedo feature, but there were a few hints of shadow
in the blocky, 'lizard skin' area around its southern edge. The Palus
Somnii was a nice albedo feature, even though the 'dark' part was lighter
than usual.
I popped in the 5mm type 6 Nagler, and I made the following note: "5 Nag: I
swear, I almost can't tear myself away from the eyepiece to take notes! The
view of the moon is that good!"
(Around this time, I took a look at Saturn in Rich Neuschaefer's AP155, and
as expected, it was mind-blowing. The Cassini was super-sharp, and the
crepe ring was very distinct.)
In Mare Frigoris, N of the crater Baily, there were many wrinkle ridges,
like veins under skin.
Dorsa Smirnov, which makes up most of the 'Serpentine Ridge', was RIGHT on
the terminator. One of the best views of a wrinkle ridge I've had. There
was a distinct peak on Dorsum Aldrovandi, and it doesn't show up well in
Rukl. Might just be the SW promontory of Le Monnier.
Mons Argaeus was magnificent. It cast a great shadow out across western
Serenitatis. NE of it, there was a line of three nearly identical,
near-conical peaks. They didn't look quite the same as shown in Rukl, but
the SE-most of them was probably Mons Vitruvius. This led me to look
carefully at Rukl, and I'm pretty sure I picked out the valley of
Taurus-Littrow. This is probably the best view of it that I've had. Man,
that area looks rugged! The valley of Taurus-Littrow was the Apollo 17
landing site. There's always been something so compelling about the story
of Apollo 17. The final flight. "The end of the beginning." "Let's see the
next generation do something like this." "America's challenge of today is
mankind's destiny of tomorrow." And so on. I vividly remember getting a
hold of an old (i.e. about 7 years old) issue of the National Geographic
when I was in elementary school, and pouring over the articles by Cernan,
Schmitt, and Evans about Apollo 17. I still remember the face of the
aboriginal New Guinean (?) on the cover. Looking at the moon tonight, and
imagining that frail little LEM coming in over those mountains... now,
THAT'S an achievement! Those abandoned descent stages gaze down upon the
21st century and say "look upon these works, ye mighty, and despair."
The Serenitatis-Tranquilitatis border region was great. I'd describe it as
'raised mare'. It was showing great, subtle low relief. Probably no more
than 100s of meters of long-wavelength relief. Flow fronts? Wrinkle ridges?
Ejecta? Lava-buried ejecta? Hard to say. You've heard of "magnificent
desolation"? This was "gorgeous irregularity". Maybe "luscious rugosity".
The pear-shaped double crater Torricelli lies within a very faint, ruined
and flooded crater, which was probably only visible at that very low
illumination.
The NE end of Rupes Altai was right on the terminator. The illumination on
it was great, it showed the corrugated shape of the scarp very nicely. The
area immediately SW of the scarp is a crazy palimpsest of overlapping
craters. What a giant's pandemonium!
Eventually, the seeing got less wonderful on the moon, and it was time to
stretch my legs and take a look at Jupiter through William Phelps' AP180.
Words, of course, are totally insufficient. Voyager-level detail.
I made drawings of the Beehive Cluster and M81/M82 while I was there:
Beehive:
http://home.earthlink.net/~marekc/m044.jpg
M81, M82:
http://home.earthlink.net/~marekc/m081m082.jpg
All in all, a really pleasant night at Foothills Park.
Marek Cichanski
Received on Sun Apr 25 23:02:34 2004
