AMATEUR ASTRONOMY:

LUNAR ECLIPSE NOT VISIBLE IN MANITOBA:

As with so many other astronomical events the first total lunar eclipse to coincide with the winter solstice since 1638 isn't visible tonight in Winnipeg as yet more snow drifts gently down to move us to the wettest year in history. Here in the Central Time Zone the umbral phase is due to begin at 12:32 am, and totality at 1:40 am. Totality will last until 2:53 am, making this one of the longer eclipses. There are two lunar eclipses due next year, so better luck next time.

For the curious you can read all about this eclipse in a wikipedia article now on the web. The full eclipse will be basically a North American event this time around with the old world and much of South America missing large parts of the event. For places other than here in the Great Canadian Snowdrift the wikipedia article gives a chart of the phases for various time zones. A good source for viewing conditions in your locale is the Clear Dark Sky website. Much better and more detailed than the average weather report. For those diehards who just have to see something NASA will host a webcam real time version of the eclipse here. Seems like a very poor substitute to me, but to each their own. There will also be a chat room at the NASA site so you can either praise or howl about viewing conditions where you live.

All I can say is better luck next year.

LUNAR ECLIPSE FACTOIDS:

As a supplement to what I have already said about the upcoming lunar eclipse here are a few "factoids" that you may find of interest. First of all, the Wikipedia online encylopedia has an interesting article on this matter, but an much better source is the NASA Eclipse Home Page. It gives just as clear an explanation as the Wikipedia site and has links to many other things that the Wikipedia site lacks.

There is, by the way, a scale for the degree of "luminosity blocking' of lunar eclipses, devised by the French astronomer Andre Danjon. It is as follows:

L=0 Very dark eclipse. Moon almost invisible, especially in mid-totality.

L= 1 Dark eclipse. Gray or brown colour. Features of the Moon only distinguishable with difficulty.

L=2 Deep red or rust coloured eclipse with a very dark central part and the outer edge of the umbra relatively bright.

L=3 Brick red eclipse, usually with a bright or yellow rim.

L=4 Very bright copper red or orange eclipse with a very bright blueish rim.

It'll be interesting to see what tomorrow's eclipse turns out like. Most of the lunar eclipses that Molly has viewed have been in the L2 or l3 categories above.

Here's a brief list of some of the notable lunar eclipses in history and the events they have been associated with.

a)Oct 9th, 425 BCE, choice of Cleon in Athens

b)August 28th, 413 BCE, siege of Syracuse

c)April 15th, 406 BCE, fire in the temple of Athena in Athens

d)Sept 20th, 331 BCE, eclipse before the battle of Arbela of Alexander the Great

e)March 23rd BCE, death of Herod (note the problem with dating the birth of Christ!)

f)Sept 14th, 14 CE, death of Emperor Augustus

g)April 3rd, 33 CE, presumed death of Christ (the possible dates reported in the Bible accord with no reported solar eclipse)

h)May 22nd, 1453, fall of Constantinople

i)March 1st, 1504, eclipse reported by Columbus

j)July 31st,1776/Jan 23rd, 1777/July20th,1777/Dec 4th, 1778: eclipses reported by captain James Cook

k)Jan 15th, 1805 Lewis and Clark eclipse

l)July 4th, 1917 Lawrence of Arabia's eclipse

As a final factoid lunar eclipses are predictable because of a phenomenon known as the 'Saros cycle'. This means that these eclipses will reoccur in about 18 years, 11 days and 8 hours. This periodicity occurs because of the concurrence of three different cycles in the Moon's position vis-vis both the Sun and the Earth. The first is the "synodic period", about 29.53 days, the usual period of the Moon's revolution about the Earth. The Moon, however, makes a revolution about the Earth at an inclination of about 5 degrees relative to the Earth's path about the Sun-the ecliptic. twice during a period of 27.21 days the Moon passes through this plane where an eclipse can occur. This is known as the "draconic month". Finally, the Moon orbits the Earth at a variable distance, varying from apogee (its furthest point) and perigee its closest point in a period of 27.55 days known as the "anomalistic month". The coincidence of these three periods occurs about every 18 years and hence the recurrence of the lunar eclipses. The complication is that each turn of the Saros cycle results in a time difference of about 8 hours vis-a-vis any point of Earth. To learn more about this go to either the Wikipedia article or the NASA article on same.

Molly

MORE MATTERS LUNAR:

Tonight, the night of the 1st and 2nd is the Full Snow Moon, but once more the weather won't cooperate here in Winnipeg- as usual, as usual, as usual. As I speak it's snowing outside, and the Moon is pretty well obscured by the clouds. In addition the windchill is predicted to reach 37 below tonight. Today the windchill was a "balmy" 32 below. Goddamn if I didn't see at least one of the squirrels that we feed out today, and the rabbit who comes to the backyard for his feeding is out and on the prowl tonight. One nice thing is that I've seen very few crows(whom I hate) since the weather turned cold. The bluejays haven't been around for weeks either. I occasionally still see a few woodpeckers and other birds. But sensible creatures like fat, lazy cats named Molly stay inside as much as they can.

So my little lunar tour is interrupted once more this cycle. In lieu of a further episode on the leisurely vacation cruise through the seas of the Moon I offer the following lunar tidbits for those who crave factoids.

A. So ya wanna be a rocket scientist eh ? Or at least an astronomer. Astronomy is one of the fields of science where citizen/amateur participation is the strongest. Many amateur astronomers spend a goodly amount of time hunting for new comets, and they often scoop the professionals. SETI organizations ask that interested people donate their free computer downtime to analysing data from such searches. And so on. Now NASA is asking for the help of amateurs once more in terms of documenting the impact of meteorites on the lunar surface. NASA's 'Meteoroid Environment Office' has been monitoring the Moon for impacts since late 2005, and so far they have found 19 hits. This branch of NASA is actually using off-the-shelf equipment available to ordinary dedicated amateurs (35 cm telescopes and store bought CCD cameras), and, as any amateur knows many things can interfere with their observations, from weather to vacations. The Office has developed data software that can run on a home PC equipped with a digital video card to extract the significant events from the endless hours of stationary video. Look to the http://science.nasa.gov site for announcements about this soon.

B. Speaking of NASA that organization announced on January 8th that all future lunar operations will use metric units. Sorta like the USA catches up with the civilized world. The use of both metric and English units led to the loss of the 1999 Mars Climate Orbiter probe. A contractor on the probe provided thruster firing data in English units while NASA was using the metric system for its calculations. Oops !

C. Speaking of oops, there's an upcoming mission to the Moon, the Lunar Crater Observation and Sensing Satellite (LCROSS), planned for early 2009 in which the upper stage of the carrying rocket will be deliberately crashed into one of the polar areas of Luna. The resulting plume of ejecta, perhaps up to 30 miles high, will be analysed by the accompanying satellite and earth based telescopes to test further the possibility that the lunar poles contain stores of ice that may be useful for future Moon bases. To date the data has been quite contradictory, with the Clementine and Lunar Prospector missions and the Arecibo radio telescope coming up with different conclusions. Now, the idea of lunar water in the form of ice is quite attractive in terms of the possibility of a lunar base, and it would be a terrible thing if this bugger didn't crash. Hence the desire to make sure everyone is speaking the same numerical language.

D. Anyone interested in the features of the moon would be happy to visit the Virtual Moon Atlas, with its various downloadable guides to lunar geography. for those of us closer to the Molly level of amateur ie nowhere near as knowledgeable the best source I can recommend is ordering the National Geographic Moon wallmap from their online store. it's the one I use the most.

Keep on shinin'

Yeah keep on shinin'

Molly

Transit Mercury:
There's an interesting astronomical event coming up on Nov 8th. This is the transit of Mercury across the disc of the sun. Mercury will transit the sun 14 times in this century, so,if you are ancient like I am, try to catch this one. For a in depth view see the Nasa web page for a web view of the transit if you can't set up a safe viewing mechanism- or if the weather isn't right in your locality. You can observe the transit directly providing that you have the proper filters on your telescope. The transit will be observable from the south Pacific through to the Western area of the NA continent. It will begin at 2:12 Eastern Standard Time, 11.12 Pacific Standard Time and will last about 3 hours.
Look up and wonder,
Molly

Sign Up for Space:
The NASA has an interesting offer at their website (http://dawn.jpl.nasa.gov ) for their latest Dawn mission to the asteroids Vesta and Ceres. Seems you can sign your name on for the data base of the spacecraft. Trouble is that the deadline is today, Saturday, Nov. 4th. If you read this before midnight comes hurry on over and send your name to the stars.
If you think this might be a great Christmas novelty gift and you can't make the deadline there's another mission coming up that closes as late as Feb 1st, 2007. You can enter the name of your lucky gift recipient, or yourself, for the Phoenix mission to Mars, due to launch next August. The spacecraft will hold the lucky names in addition to a silica glass DVD holding many of Martian related works from the 19th and 20th century. The title will be 'Visions of Mars'. If you want to fly with the stars or send anyone else to the stars hustle on over to http://planetary.org/phoenixdvd to sign up for this bit of virtual tourism. It's travel with a bang and no passport required.