Get your ticket ready, we are going to Mars on July 17 if all goes well. Here's a copy of my boarding pass obtained from NASA. :) Some time ago, NASA created a cache of names to put on the Mars spacecraft that will land on Mars. They issued these boarding passes to those successfully registering their names.
POSTPONING OUTDOOR ASTRO WORK
By 8 am the heat has reached 100 degrees and outdoor work on the non-functioning Celestron mount is postponed. Rain is predicted with extreme high humidity levels already present. At this rate, the blog name could be changed to "Indoor Astronomy."
STILL NO QUOTE ON BIG MIRROR
The optics company wrote back regarding the quote on the large finished mirror. They only said they will be in touch. They are probably over their heads in orders.
PLANETARY GOOD OR BAD?
Research continues into big Dobs and there is a decided lack of planetary use. The ongoing contention is that average mirrors of big Dobs can be used at the lowest possible power for DSO thus minimizing imperfections. This confirms the trend of shorter and shorter FL scopes.
FORGET GOTO
Big Dobs can inexpensively find objects using smart phone apps and a machine that determines angles, as a substitute for expensive GOTO systems. Telescope technology is rampantly changing.
BIG MIRROR SCRATCHES
The letter from the owner of one optics company states the bigger the mirror, the more embedded deep scratches it will have that occur during polishing. They are trying to convince people that such scratches are unavoidable and unimportant in the final image. This is certainly believable with less than billion dollar NASA white rooms of ultimate cleanliness. Other sources definitely have different opinions. As a telescope mirror maker for many decades, I know it's vitally important to polish and figure the mirror in a clean room at a different location, and to use the highest quality optical grade rouge and cerium oxide polishing compounds, among other ATM handling techniques. Of course budget mirrors are not going to have the quality control, or pricing, of NASA.
COMPASS BE DAMNED
Smart phones generally have compasses that may not give accurate results. Many star planetarium programs that use the internal compass are known to have failures and drift off cardinal directions. Smart phones and iPads generate their own EMI and can interfere with their own compases. Telescope mounts have metal compounds that interfere with magnetic fields. This can throw off the compass and wireless communications such as WiFi and GPS.
Measurements show the deck can hold some of the largest commercial Dob telescopes with the limitation being the scope's elevation and the floor depth from the skyscraper to the drop-off. The range of consideration is probably a telescope 18 to 24-inches diameter at f/3.3. In the larger example, the rocker base spans 788 mm on the longest side, or 31-inches. The typical new deck span is 45-inches from the granite safety lip to the skyscraper wall, sufficing for the largest rocker base with a clearance of 14-inches - 7" on each side of front and back.
DOB LUCKY IMAGING
Lucky imaging is taking off with owners of large Dob telescopes without drives. An object is placed in the corner of FOV and allowed to drift to the opposite corner. Some software like FireCapture has a feature to center the object and keep it there as long as possible, even the object is drifting from no drive. Thousands of images are obtainable by recentering the object and repeating the process. Processing removes the motion. Exposures are usually 1 second or less.
ASTRO ORDER CHALLENGES CONTINUE
The large accessories order list was sent back to the company for the third time and thus far no response. The manager states almost all items are sold out but they can be at hand in a month. A second company confirms all those "stay-at-home individuals" as a result of rules governing the Corona Virus, are pursuing their astronomy hobbies and buying pretty much everything available.
VENUS FLOPS TO AM
Early this morning a small break in the overcast clouds had Venus showing at a relatively favorable position. Unfortunately all Venus filters for cloud study are sold out. Ever since planet Venus flopped over to the morning sky, the new position in the East is ideal for deck observations.
ASTRO GYM
With ultra-hot weather conditions and rain, and the inability to get key accessories for astroimaging, the hobby has become excessively sedentary. For this reason, I'm erecting a workout Gym amidst the observatory.
