This, that and the other

This week, we have sort of a Hodge-podge of information.

As you may be aware, the astronomical community was all agog last week following along as the Philae lander separated from the European Space Agency's Rosetta robotic space craft that had caught up with and orbited Comet 67P (it is also named for two Russian astronomers who discovered it, but nobody can pronounce their names).

It is known that the craft bounced at least three times before coming to rest on the surface of the comet--and, no, it wasn't supposed to bounce.

Despite the fact that it may be partially laying on its side, and almost in the shadow of a cliff, it has been sending back some really amazing photographs of it's surroundings and the comet's surface.

If you would like to follow along, point your favorite browser to: http://www.esa.int/Our_Activities/Space_Science/Rosetta.

For our star-gazing, we turn our attention to another old friend, Cassiopeia, the Queen. She can be found these autumn evenings high in the north looking like a squished letter "M" just to the left of Perseus.

If you are out looking about an hour after local sunset--now that Daylight Savings Time has gone away, that won't be too late--it shouldn't be too difficult to find her, although you will probably want to dress warmly.

Right now she is high overhead. In six months she will be just barely above the northern horizon and will have her more recognizable "W" shape.

Just as Cassiopeia is high, another of our northern friends is low on the northern horizon, so low in fact that if may not be possible to see all of it. The asterism of the Big Dipper. The bottom two stars of its dipper are either below or scraping the horizon depending on your viewing location.

Lastly, this is for our Lord of the Rings friends, specifically those who are fans of "The Hobbit."

I have often been asked about how to calculate Durin's Day, the first day of the year for the Dwarves.

Taking the information from the book in the chapter titled, "A Short Rest," these conditions must be met. 1. The Sun and the moon must be visible in the sky at the same time; 2. It must be the last moon of autumn; and, 3. It must be on the threshold of winter.

Let's take them from back to front. The first day of winter is December 21. Next the last moon of autumn is the new moon closest to that date, which is Nov. 22.

Now, for the hard part, being in the sky at the same time.

It would seem that the Dwarves New Year does not depend upon a calendar day, but the day when the just-past new moon is visible in the sky along with the setting Sun, and that will be hard to predict because it depends on seeing something.

Now, from experience we know that it takes at least two, perhaps three, days for the crescent moon to be visible after the new phase, and because it will need to overcome the light of the still-shining Sun, that could push it back another day or so.

Thus, the earliest possible date for Durin's Day this year is at least Monday, Nov. 24, or at the latest, Tuesday, Nov. 25. Unless Tolkien used the ancient Celtic calendar -- and he was a professor of Celtic studies and language -- that puts the beginning of a season not on the solstice for the first day of a season, but on the cross-quarter day between the equinox and the solstice, which is a whole other kettle of fish we will need to examine later.

SKYWATCH: New moon, Saturday, Nov. 22. Moon and Mars in conjunction on Tuesday, Nov. 25.

NEXT WEEK: More astronomical blathering.