At sunset this evening the Moon will be less than a day past new, about 20 hours old and only 0.7% illuminated. It is possible, if somewhat challenging, to spot this very thin crescent in the evening sky deep in the bright glow of sunset.
This evening the Sun will set at 18:39 and the Moon will set at 19:21, about ten degrees behind the Sun. Thus a low and clear western horizon is a necessity for locating the Moon tonight. Optical aid will also be very useful, once the correct area is located the Moon can often easily be found by sweeping the area with binoculars. A small, rich field telescope with a field of several degrees across can also be used.
The effort is aided a bit by the presence of the bright planet Mercury in the sunset this evening. The planet will be seven degrees higher in the sky and just a bit north of the Moon. If you find Mercury at 19:00HST, the Moon will be 5 degrees below the planet and four degrees to the south in azimuth.
In several cultures with lunar calendars the spotting of a young crescent Moon like this marks the beginning of the month. Often Moon sightings are used to determine religious holidays and other important events of the year. It is also an good challenge to practice your observational skills. have fun!
Davis-Monthan AFB was my last duty station, I spent a year working the flight-line there. After I was out of the military we visited that flight-line again, this time for the annual 1993 “Lightning and Thunder” air show. A good day, with fun displays and a performance by the Thunderbirds…
Another pass on Jupiter this evening, the string of decent seeing nights has continued. I am working on improving the setup and my technique. I had been using a diagonal to mount the camera… That is gone. I futzed with the collimation a bit, but it really is quite close. I need to figure out how to get a barlow into this arrangement, do they make a rear cell thread barlow like the focal reducer?
The seeing really does appear to be my greatest limitation. Planning a trip to better seeing in the next couple weeks.
It is not an Easter egg, but this will have to do, the closest I have for the day…
After a stormy Friday night we had clear skies and decent seeing over Waikoloa again last night. Again I set up the telescope for a little planetary photography. The seeing was marginally better, and so is the resulting image.
The night also featured three moons in close to the planet. Io can be seen alone to one side of the Planet while Europa and Ganymede form a close pair. Ganymede is the larger moon and slightly closer to the planet
I really need to do this from the summit under good seeing some time.
Dawn has been in orbit around Ceres for over a year now, having entered orbit back on March 6th, 2015. Most of the dwarf planet has been photographed and mapped in high resolution now, creating beautiful imagery that reveals a great deal of interesting terrian. As we have seen with other dwarf planets like Pluto, these little worlds are surprisingly dynamic places, hardly the dead rocks one might have expected.
The bright features in Occator crater have been revealed to be some sort of cryovolcano. While not certain, the bright is likely to be water ice, or perhaps a briny, salt and water mixture. There has even been some evidence of vapor observed over the crater, possibly from sublimating ices.
Jupiter passed through opposition back on March 7th. Thus the giant planet is high in the sky through much of the night, well placed for observations.
I was thinking of going to bed, but it was a hot windless evening in Waikoloa, not much point in trying to sleep before it cooled off a bit. The dead calm conditions made me think… What is the seeing like? A question only an amateur astronomer would ask.
Turns out the seeing was pretty good. The typical horrible seeing in Waikoloa is 2 to 3 arcseconds or worse, when the trades are blowing it can be quite bad. I suspect the seeing was 1 arcsecond or better last night, the view of Jupiter in the eyepiece was quite pleasing. Putting a camera in place of the eyepiece yielded video worth the effort in processing.
This full moon will feature a penumbral lunar eclipse visible across the Pacific region. It will be well placed for observers in the Hawaiian Islands where the entire eclipse from beginning to end will be visible. Do not expect much, penumbral lunar eclipses involve only a slight dimming of the Moon, it is unlikely to be noticeable without instrumentation.