Townsville Astronomy Group

Hi Group,
Well something seems to have gone wrong with our old saying, 'good today but better tomorrow'. I've got to admit that the atmosphere is just a bit thick for good viewing!!!!

Mars reaches opposition today, 30th January, 2010 at some where around 14 arc seconds angular diameter. Not as good as it can get but good enough to have a good look from our close-up vantage point if we could only get past the first few miles of tropical soup being dished up by our cyclonic friend in the Gulf of Carpentaria and it's not over yet folks - more to come I feel.

Our first 'Blue Moon' for this decade and once again - not good! My apologies to the folk expecting us down at the Strand but this is beyond our control I'm afraid. However, all is not lost as we have another chance to view a so called 'Blue Moon' in March.

'Blue Moons' are not that uncommon but it takes a special set of circumstances to put 2 of them in one year! The Moon has a 19 year cycle called the 'Metonic Cycle'. This cycle has the phases of the moon occuring on the same dates and in the same spot in the heavens in a year. So, over a 19 year period we will have 228 months but in that time we will have 236 full moons. It stands to reason then that those 'left over' or extra Full Moons must fit in somewhere so we have the occassional month with two (2) Full Moons. The shorter month of February can't fit 2 Full Moons into it's 28-29 day period so most of the surplus moons fall in months with 31 days (mostly) as in this year where we have one in each of January and March. The last Moon in the month is the 'Blue Moon'!!! Remember that one 'synodic period' is 29.53 Days so it is possible to have them in a 30 day month but not by much (it's a pretty tight fit).

There's a couple of good sources of information on this topic in the form of 'Exploring the Moon' by Steve Massey and I think a must for anyone 'The Astronomy Year Book for 2010 - Australia'.

Well that's all from me this time.

Look up and enjoy!

Lex.
Obi-One

We can see stars!!! Lovley Moonrise over Magnetic Island last night, with Mars shining brightly to its upper left
Bella will be christened tonight (Monday) .... Moon too bright last night to view planets and stars.
Will start to tackle the Argo Navis today

January's full moon is also called the wolf moon, according to Native American tradition associating this month's full moon with wolves howling in the cold midwinter. (Take a moon myths and mysteries quiz.)

The 2010 wolf moon will appear 30 percent brighter and 14 percent larger than any other full moon this year, because our cosmic neighbor will actually be closer to Earth than usual.

The moon will be at its closest perigee—the nearest it gets to our planet during its egg-shaped orbit—for 2010 at 4:04 a.m. ET Saturday, reaching a distance of 221,577 miles (356,593 kilometers) from Earth.

At its farthest from Earth, the moon is said to be at apogee. Perigee and apogee each happen generally once a month, but the moon's wobbly orbit means that the satellite's exact distance at each of those events varies over the year. The moon's phase can also be different during each apogee and perigee.

"This month has the largest full moon of 2010, because it coincides with the special moment when the full moon happens to occur on the same day as it is at perigee," said Marc Jobin, an astronomer at the Montréal Planetarium.

And in a remarkable coincidence, Mars is at opposition Friday—directly opposite to the sun in the sky—so that as the sun sets in the southwest, Mars rises in the northeast.

Around opposition, the red planet gets closest to Earth. This year Mars swung by at just 61 million miles (98 million kilometers) on January 27, and it will still appear remarkably bright during the weekend sky show.

"To the naked eye it will appear as a bright, orange-colored star right next to the full moon—the pair will jump out at you for sure," Jobin said.