By Gran Turismo to Tranquillity

Jay Reynolds Freeman

All three setups so far have been at Lick Observatory, in support of the Summer Visitors Program. Summer evenings on Mount Hamilton are often superb, and September 6 was an especially fine evening. I noticed a temperature of 102 F (39 C) on the high school sign as I drove up Quimby road late in the afternoon, and that translated into shirt-sleeve conditions on the mountain top all night long. The air was calm, as well: I usually bring a small telescope on a very robust mount to Lick, so that I can be sure to be able to show things to visitors even when the wind is blowing and everything is vibrating, hence the Gran Turismo was seriously over-mounted on my Losmandy G11, but it was not necessary this time. And as sometimes happens in such conditions, the seeing at dusk was superb.

The Gran Turismo is tiny. With the sliding dewcap telescoped back over the skymost tube section and the large, long focuser racked in for transportation, it measures only 71 cm (28 inches) long, and the different sections of the tube -- which come apart for even more compact transportation, if you wish -- are of different diameters, rather like a cartoon telescope, so that the overall effect is of great compactness. The instrument is easier to set up and handle than my Vixen 102 mm f/9 fluorite, or my Vixen 90 mm f/9 fluorite, or even my Orion 120 mm f/5 rich-field telescope, notwithstanding that the latter has a shorter -- though not less bulky -- tube. The Gran Turismo is heavy, though -- there is no denying the weight of that lens, and the rest of the optical tube assembly is solidly built. Nevertheless, among small refractors, this instrument is a high point in portability per unit aperture.

Roland Christen's optical craft is well enough known that it would be superfluous to rant about how good this telescope's optics are. Suffice it to say that the instrument showed no trace of color, split double stars with aplomb and with textbook-perfect diffraction patterns, and showed a wealth of fine detail on the Moon and Jupiter -- probably more than I could appreciate, since I have never been much of a planetary observer and do not really have a developed "eye" for it.

What does one show visitors at a summer star party, anyway? The area where we set up at Lick is to the east of a long building, which blocks the low western sky, and some of the horizon is blocked by trees and other buildings. Furthermore, though Lick often has wonderful seeing, the sky so close to a major urban area is rarely truly dark.

As you might expect, I stick mostly with the bright and the spectacular -- on these three nights with the Gran Turismo, I have shown the Lagoon Nebula, the Omega, M22, M13, the Ring Nebula, the Dumbbell, the combination of M31, M32 and M110, M6 or M7 in the early evening, and perhaps the Double Cluster later on. All these objects show well in low to medium magnification fields in the Gran Turismo. I usually use Vixen Lanthanum eyepieces at public star parties, both because they have a uniform long eye relief and because they are not my best eyepieces, so I have less worry about mascara and fingerprints getting on them. I have a 30 mm, which is actually a wonderful wide-field eyepiece, a 24-8 mm Zoom Lanthanum, which keeps a reasonable apparent field of view throughout its magnification range while its "zoom" feature saves changing eyepieces often, and a 5 mm for a little more magnification.

Double stars are spectacular as well -- I usually stick with pairs that show color, as a matter of interest, like Albireo, epsilon Boo or eta Cas. Zeta Aqr is not colored, but is an excellent example of a moderately close (for 130 mm) pair of equal brightness, that can give newcomers to astronomy a sense of what looking at double stars is about.

Sometimes I show something more challenging. A wide-field view of M33 usually allows everyone to see at least something, since the very core of the galaxy is fairly bright, and the subtlety of so many stars so faintly seen brings oohs and ahs. So also does the thin edge-on view of NGC 7331. (On my own, I did find a trace of Stephan's Quintet at 102x, but it was very difficult to make out in less than perfectly dark conditions, not so much because the sky was bright -- at 102x it appeared plenty dark -- as because of ambient lighting from the Lick Observatory main building itself.)

The real treat of the evening, however, was the Moon. I was pointing at it as the sky slipped into twilight, while the Lick visitors were still being entertained by the concert. The terminator lay just selenographic west (I will use selenographic directions herein, so that "west" means "toward the eastern horizon of the Earth") of Mare Tranquillitatis, with the eastern end of Rima Ariadaeus exposed but the bulk of the rille trailing off into darkness. The seeing was excellent, with moments of crystal clarity, even at 292x (Takahashi 2.8 mm Orthoscopic eyepiece). In this area there is an easily recognized arc of smallish craters, comprising Sabine, Ritter, Ritter B and C, Manners, and Arago, which I have always been fond of, because in 1951, a science-fiction club which I later belonged to (in the 1960s and 1970s) presented a claim to this region to the United Nations. It was denied, but when the Apollo 11 mission landed nearby in 1969, the Elves' Gnomes' and Little Men's Science Fiction, Chowder and Marching Society of Berkeley attempted to bill NASA ninety cents an hour for parking.

Pay-lot fees or no, this arc of craters is a good entry point for observers wishing to study the area of the Apollo 11 landing, and the conditions on September 6 were good for doing so. The area is shown on Rukl chart 35, with some features of interest on charts 36 and 46 as well. Draw a line from Arago to Sabine, and turn exactly 90 degrees to a generally easterly heading. Whether that turn is left or right depends on whether your telescope is inverting or not. Tranquillity Base lies on that heading, about 60 percent as far from the center of Sabine as is the center of Arago.

There are a few useful features for identifying the location more precisely -- not too many, for that first landing was in an area deliberately chosen to be free of hazards. But a good place to start is with the small craters Moltke and Maskelyne G, the first a little south of the easterly-pointing line, and the second somewhat more north of it. Draw a line from Moltke to Maskelyne G, and a bit northwest of its center find the smaller crater, Armstrong (formerly Sabine E). Its 4.6-Km diameter showed steadily as a crater with a shadowed interior in the Gran Turismo.

Now aim from Armstrong back toward Sabine. About a third of the way there, find the smaller crater, Collins (formerly Sabine D). It is 2.4 Km in diameter, and showed in the Gran Turismo in moments of steady seeing. About half way from Collins to Sabine is Aldrin (ex Sabine B), whose 3.4 Km diameter made it perhaps a little easier to see.

With these three craters located, draw a line from Armstrong to Collins, there turn 70 degrees toward the south, and proceed about two thirds of the distance from Armstrong to Collins. That is the location of Tranquillity base, and though there is nothing to see there in the view through any telescope that I have ever used, using these three small craters, named for the flight crew, as guides, should allow you to locate it within a reasonable walking distance, even in a space suit.

My records of lunar observing are not well organized, but I am not sure I have ever seen all three of Armstrong, Aldrin, and Collins craters.

Now let me see, the Apollo 11 LM descent stage has been there for more than 39 years. At ninety cents an hour, the parking fees would be well over 300,000 dollars, plus interest, even if we did not issue a ticket ...

-- Jay Reynolds Freeman