NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: 1st lunar attempt
From: Herbert Prinz
Date: 2003 Apr 25, 18:10 +0000
From: Herbert Prinz
Date: 2003 Apr 25, 18:10 +0000
Doug - Hello, again. I wish that somebody else would have mentioned this besides the good general recommendations that you got, as I hate to be the party pooper. But, since you asked for _practical_ advice, let me point out that we are approaching New Moon on May 1st. You probably missed your chance this month. First of all, you can forget evenings, for now. In the mornings, your problem is that by the time the Moon is high enough for your circumstances, twilight sets in. No need to indulge in theoretical speculation which object might be most suitable. You have to work with what is there; in all likelihood, this will be Mars. You have to be extremely fast and efficient - not exactly the ideal conditions for a beginner. On Sunday morning, you may get as little as 10 minutes for a decent star or planet observation. Since I don't know your latitude, I can't tell for sure. Once the sun is up, I would say, your choice of objects is even further limited. Although it is possible to observe the Moon at a distance of 56 deg (Saturday) or even 45 deg (Sunday) from the Sun, one needs a perfectly clear sky, good instrument, and, again, some skill. The altitude observation of this moon with a make shift artificial horizon I consider impossible. If your mountains are anything like the ones in which I grew up, you will have low hanging clouds and a hazy sky in the morning, preventing you from seeing the Moon at all. But in the afternoon, the sun is high and bright and the moon low, setting early. Lest you want to risk that your first lunar observation becomes a totally frustrating experience, I would suggest you put it off until the Moon is in first quarter. I also suggest not to try immediately to do everything at once. Start out with just measuring the distances; don't measure the altitudes, as you can compute them from your known position. This does not take away anything from the experience, since you know that you _could_ measure the altitudes if need be. Later, you can put together all the individually obtained skills for a simulation of the complete procedure. Besides, computing the altitudes probably is the more authentic procedure for land based observations, anyway. If you absolutely can't wait and you are the kind of person who likes to mess with sextants and oil filled bowls in the dark before the cock crows, on Saturday, around 4:30 Local Standard Time you may find the right conditions for an observation of Moon and Mars. Venus, being a morning star these days, will be out by then, but too low in the sky. She will rise higher than 10 deg just about sunrise. Not too many of the usual lunar stars seem to be in a good position during that small time gap that is available between moon rise and sunrise. Check out Antares, avoid Altair. On Sunday, Venus, will appear closer to the Moon, in fact too close to be without problems. Good luck! Herbert Prinz "Royer, Doug" wrote: > I'll be useing an > artificial horizon for this.I plan to attempt this on Sat.and/or Sun if > conditions are right.I live in a mountainous area at about 2100 ft. > elevation.Should I take something into account other than the basic stuff > because of the elevation?Because of the mountains the observed bodies > altitude will be between 11*-17* before I can see them.On the 1st attempt of > this should I use the sun and moon,the moon and a planet,or what do you > suggest?The moon where I live will be visable along with the sun in the > morning and late afternoon and evening.What time do you recommend would be > better for this?Is this easier to do in the daylight or muted light since > I'll be useing a horizon?I don't expect to get this right but need some > advice on makeing this as easy as possible to do.Any other pointers would be > appreciated.I don't need to go into the calculation aspect of this yet but > need as many pointers of the mechanics of the proceedure.All the past posts > were of great value but lacking a bit on the mechanicall aspect.I would > wecome all pointers on list or off. thanks